Argus 3 (BST) teardown and repairs

[Bill W]

The Argus 3 was a fire fighting camera made by Marconi and e2v mainly between 2002 and 2006, hence the name change.  The version covered here is the most common 'yellow' version which used the Raytheon BST core and was 320x240 pixels.  The other versions were 'blue' with a Raytheon ASi (160x120) and 'orange' with a Lockheed VOx (also 320x240).

As I have repaired a couple of these recently, I took some photos along the way to give a 'teardown' and provide a repair story.  I will post slowly so there is a chance to reply roughly in the time line.  The teardown / tour also appears on www.fire-tics.co.uk/project2

So the camera here was reported as 'not working' which can cover a whole load of actual conditions from totally dead, through black, white or grey screens to 'noisy but grey' screens.  To most users these are all 'not working' although you can probably guess what each is due to.

So it arrived, and although not from a fire service it still needed a good clean before even holding it.  The casing and box mainly stayed in the shed !  Initially I powered it from  croc clips on the battery terminals from a PSU.  A lot can be learnt from the current draw, and in this case all was well (10V, 3A current limit, took 850mA initially and then settled to 450mA).  The picture though was a rolling mess.
On these cameras the screen runs off the external video so  not surprisingly the external feed was the same.  It was however thermally sensitive, a soldering iron could be seen flying up and down the screen.  On the scope the video was clearly out of sync and variable field times.

So I am thinking something to do with the TV line standard switching.  As that is easier for me to fix internally (and it was still smelly) I took it apart.  In the end I could have corrected it from outside with the customer software, but would not have been able to fix the rest.

So after giving it a bath, on with the pictures....

[Bill W]

The first set are just getting into the case and a few pointers to what is accessible on the sealed case.  The screws are all hex head, 2mm or 2.5mm.

First image - shows how to remove front panel to access BNC video and alsos ee if there is a transmitter
Second image - Connectors and functions around the lens window.  That RS232 (Fischer) connector had a dust cap but everyone loses them and they can just fill up with crud.
Third image - shows how to remove the handles.  The cameras also came with side straps in which case there's two big screws each side as well.
Fourth image - these screws only let you remove the bezel and window, so OK to clean it but no use for disassembly.

I have also added the battery and base contact pinout.

The base power contacts are useful as they bypass the on/off switch circuit, apply power and the camera will start.

The charge contacts need some care, as the charger control is in the camera but the power supply was external, so the supply here is 1A constant current, up to 8V.

Bill

[Bill W]

Now the fun starts for proper.  There are 14 screws holding the case together (arrowed in the second photo).  The camera chassis is attached to the front part of the case, so it is best to remove the back.

[Bill W]

The split case.  The LCD and buttons cable is marked with the green arrow, the chassis is held in with the 6 fixings arrowed in purple.  The coin cell is for the clock IC and also memory backup, so a camera that has lost its' time (reset to 1 Jan 2000) or that will not store pictures can be repaired with a new battery. Given most cameras were built around 2005, the coin cells will now (2021) be getting near end of life.

Second image is running the chassis & front on the bench, with the pins for the buttons shown to 'hot wire' the camera.  Just short the end two pins shown to pretend to be the 'on' switch.

These fixing varied over time, from rubber mounts (which let the chassis bounce around too much) to pillars (fiddly) and eventually spacer posts fixed into the chassis plate.  Electrically there is an FFC connection and a power connection from the front case to the chassis to remove (third image) while lifting the chassis out.

Fiinal image, the removed chassis.  This image has the power input connector shown as well as the 6 way 'export test' connector that I will come back to later.

The 6 way is marked up for the wire colours from the front case:

White    1	Unswitched power in +ve from base pin
Red    2	Battery +ve - to on/off switching
Black    3	0V / case / ground
Yellow    4	Charger +ve from base pin
Purple    5	Battery Thermistor
Blue    6	Battery 3rd pin - for AA pack detection

[Bill W]

As for the repair, I got connection for RS232 and could read out the camera settings.   This function is available on the 'public' software that came on the Argus 3 CD, a copy of which is available here http://www.fire-tics.co.uk/Argus3_CD/index.htm

Among all the usual settings, of note was it reported as 625 line but was not enabled to switch between 525/625.  It thought it was January 2000, which means flat backup/clock battery.
 
Once inside I could look at the core video which was fine, and 625 line standard.  Having persuaded the core to be 525, all was well.  So it was running a mix of 625 on the core and 525 on the rest of the camera.


So how did it get like that?
Maybe after switching over the battery went flat as a lot of things only get saved during the turn off, or the user panicked, so the core changed but the camera did not.  Given the flat coin cell more likely seems that on starting sometime the settings storage for the camera might have been lost and so reverted to defaults (525 & no switching). 

So changed the coin cell and did the full factory setup & tests. After this I could switch back and forth as expected.

A couple of other things had also became apparent.  The spot temperature was reading low (37°C for 54°C) and the lens iris was stuck (as this is common I had checked before putting it all back together).   
So onwards.....

Bill

[MapleCoast]

The BST Raytheon core looks different from the 300D Raytheon BST core, this is the first time I've seen a variation of the design as there is no chopper wheel. Thank you for sharing this.

[Bill W]

There is still a chopper wheel. In the pictures it is mostly hidden by the lens mounting but a little sticks out below.

This is the standard BST 'OEM' kit, but without a detector PCB.  When building a whole system in house Raytheon would make their own adjustments to suit, but equallly were happy if camera builders wanted to make their own detector PCB.

We still bought the 'SECCA' processing PCB, detector, some connectors and the wheel.
By the time we had made our board, sent it to Raytheon for the detector and got it back to the UK there were a fair few air miles on those parts.

Bill

[Lambda]

The BST Raytheon core looks different from the 300D Raytheon BST core, this is the first time I've seen a variation of the design as there is no chopper wheel. Thank you for sharing this.

Yes, as said Bill, there is chopper wheel:

More visible indeed here...
http://www.fire-tics.co.uk/project4/index.htm

And from the picture given by Bill.

[Fraser]

Thanks for your excellent informative posts Bill

I have two A3’s awaiting refurbishment and your posts will be very useful 

Fraser

[Fraser]

Bill,

One feature of the BST technology that some users do not like is the halo effect around a hot target. Did you ever see any work done to remove the Halo effect ? I am thinking a totally opaque chopper wheel might improve the image in terms of Halo, but at the cost of dynamic range. I have made solid chopper wheels but sadly did not have time to test them for halo effect before needing to focus on other commitments. If there is a way to reduce the halo effect, I think the BST technology may be more acceptable to users who are used to relatively ‘flat’ images with no halo. The BST core is a lovely bit of kit that I wish had been developed further, but sadly it was not to be.
The current chopper wheel design works well but maybe there is the opportunity to develop different chopper wheels, as E2V did with their more specialist cameras.

Fraser

[Bill W]

One feature of the BST technology that some users do not like is the halo effect around a hot target.

For the 'fire' market it was more the other way round - they loved the BST 'halo' to the extent that some of the current FLIR enhancements are heading that way.  I did not try a P4428 chopper in a BST (maybe I should .....) but would expect it to be halo free.  Remember that fire cameras all had an iris (aka Thermal Throttle' ) which would mitigate the problem if automatic or else used correctly.

The translucent / diffused chopper wheel acts in a similar way to applying a ~20 pixel unsharp mask to the image.

Bill

[Fraser]

Interesting comment on the P4428 chopper wheel Bill 

I think it would be worth comparing the images produced by the translucent and solid chopper wheels. As we have already seen, it is possible to 3D print a replacement chopper wheel that is opaque so anyone buying a camera or core can decide whether to keep the translucent wheel or change to the solid type to remove the Halo I only mention the Halo as it has been raised with me on a few occasions and some users think that it is a feature of the actual imaging array and they do not like its presence. I can see that in a Fire Fighting situations, a Halo around a casualty would be very useful in highlighting them against the background. I have seen edge detection algorithms that are used to artificially add a 'halo'/edge marker to people in order to highlight their presence in a scene. This is desirable in SAR situations where a target may not be an obvious human casualty.

Fraser

[Bill W]

A couple of other things had also became apparent.  The spot temperature was reading low (37°C for 54°C) and the lens iris was stuck (as this is common I had checked before putting it all back together).   
So onwards.....

The spot temperature was as simple as crud on the lens of the sensor.  A clean up improved this enough (48°C on 54 °C, and 83°C on 100°C) for the owner not to want a new sensor.  The Raytek module only has normal coatings so these had degraded in use.

The stuck iris was a bit more surprising, not the usual oil & grime between the two leaves (oil from the motor bearing) but the slot for the leaves had closed up.  See first image
Maybe had a drop or just movement over time of the machined parts & adhesives
The front element block can be removed, so took that off and slightly filed it to sit straight again and the iris ran fine with the factory speed settings. There was certainly some glue in the face along with the screws.
See second image

Bill

[Bill W]

A few more internal images...


First a front case, fully loaded with spot temperature unit and the US version of transmitter (analogue, 2.4GHz, 200mW, FCC 90).

The chassis connects to the front board by the 1mm ribbon, then all wiring is from that PCB for connectors:
BNC for Video out
Fischer 102 series for RS232
'ambient' temperature yellow wires (a thermistor)

By comparison, the 'no options' basic version with the various blanks annotated



Bill

[Bill W]

PCB's in more detail

1 - Video Processing PCB takes the digital data from the BST core and adds colour, graphics and data to it.  Collects signals from spot sensor, battery voltage and internal temperatures, also controls the display.
Output analogue video (for BNC or rear LCD display)
Output controls to BST core and iris settings

2 - 'Motherboard' PCB for power switching (on/off and 10V supply), battery charge control and interconnections.  Also has a humidity sensor to alert the user to extreme wet - hopefully before the BST sensor is damaged.  It can be a nuisance over time as the humidity rises anyway and can give a false alarm.

3 - SECCA PCB.  The Raytheon processing board which carries the sensor calibration so is paired to the BST detector.  It outputs both analogue and digital video, in the Argus3 though the digital is used.  The SECCA has an 80 way 'Airborne' WBS80 connector, which seems to be obsolete now.
A couple of faults seem common, one is failed tantalum capacitors (mainly on the earlier version) and damage to the inductor '223' by the PCB holder.  Can happen if the camera is dropped and prevents operation with low battery volts as it is the step up part of the main voltage SMPS

4 - Detector PCB.  Although the BST core did offer a Raythen Detector PCB, Raytheon were happy to release their design to allow camera builders to make up a shape to suit their camera and include any other features that they wished.  The row of pins below the detector are where the SECCA is connected via a transition PCB from the 80 way connector.
Various functions are annotated on the PCB and in the image.  The main interest for hobbyists is the ability to use just this as a stand alone camera and access the BST video and control the core direct via the BST RS232 and software that has become public.
The PLD gives a phase shift on the chopper signal (as the sensor is in a different place to the Raytheon default) and operates the lens iris to close if the digital data overloads on too many pixels.

[dennis1573]

Regarding the opaque chopperwheel and "Halo" effect, i did some tests with my Argus 3 BST core.

I made a chopperwheel, using shrinkwrap and graphite paint (Graphit 33 by Kontakt Chemie) for the Spiral.
I designed the Chopperwheel frame in sketchup 3d.
I have attached the .stl file and some pictures, for anyone who is interested.
It has to be printed 2 times, and the shrinkwrap is then "sandwiched" between the 2 halfes.
I put the original chopperwheel on a photocopier, to get an exact copy of the Spiral.
I cut the transparent part out, and used it as a mask to spray the Spiral on.

Here are 2 test videos i made, recorded with my ImmersionRC Powerplay DVR

Original Chopperwheel (With "Halo" Effect):
https://youtu.be/DVV6sw-Xg-E

DIY opaque Chopperwheel (No "Halo" Effect):
https://youtu.be/enszw6B4wGQ

[ArsenioDev]

WOW that's an EXCELLENT demo of the chopper and it's masking. I wonder how hard it would be to print a custom thin monolithic chopper wheel. Prob pretty trivial

[Bill W]

Another option is thin (0.5mm or less) unclad FR4.  It does not need painting.
It is what was used for P4428 and Argus1 choppers.

Those however would benefit from a balance weight, whereas the thin film ones are OK without.

Bill

[dennis1573]

I had some time, and did some more tests.
I redesigned the Chopperwheel, the Spiral is now also printed so this Chopperwheel has to be printed only once.
The Spiral is only 0.3mm high, and so light that balancing isnt needed.
Ive attached some Pictures, and the .stl file for the Chopperwheel V2.
Unfortunately my 3d printers extruder is made of PLA and a bit broken...
So the Chopper i made, looks a bit sad... but it works fine.
I printed it using: PLA, 0.3mm layer height, 100% infill.
I waited for the heated bed, to completely cool down before removing it.
You really dont want to bend it, and potentially scratch your sensor...

Here is another testvideo, this one is a bit longer:

https://youtu.be/Ren3Ua61UEU

I forgot to mention, all videos were made with the Iris stuck in the fully open position.

[ArsenioDev]

WOW that is some VERY nice video from an older BST stack, the loss of the black haloes really does a WORLD of help.

[Fraser]

I agree, for general use the solid chopper wheel improves the image tremendously 

Dennis, thank you for sharing your design. My only concern is the 0.3mm thickness used. Maybe a little thicker would be safer ? As to balancing, if such is required it just needs a small piece of lead tape adding to the wheels centre 

Forum member Spirit designed a 3D printable chopper wheel as well. His design included balancing as I believe his design software provided a weight distribution compensation feature.

I have always found the Raytheon BST core used in Argus fire fighting cameras to produce very nice imagery, albeit with the Halo present. The Cadillac DeVille is less impressive thanks to decisions made regarding the image presented to the user.

I note quite a bit of dynamic noise in the images from your camera Dennis. I do not recall seeing that on my Argus 2 and 3 cameras. It may be worth further investigation but Bill W will be able to advise if such random noise is at the expected levels.

People should not consider BST an old and therefore poorly performing technology. It was actually pretty good  No FFC frame freezes in a time when an FFC flag was deemed essential for microbolomter based cameras  plus, of course, 30 frames per second imaging 

This work has encouraged me to dig out some of my BST cored cameras and get the faulty units running again. I have a fair few !

Fraser

[Bill W]

I note quite a bit of dynamic noise in the images from your camera Dennis. I do not recall seeing that on my Argus 2 and 3 cameras. It may be worth further investigation but Bill W will be able to advise if such random noise is at the expected levels.

I agree it does not look quite right - I wonder if the peltier is running OK ?  Dennis, can you monitor the current consumption for the core as it turns on ?

In ambient temperatures the detector can get lucky and be near 30°C anyway.

Also of note in the video is the sun-safe nature of the BST (thick lump of ceramic) compared to a microbolometers' thin slice of silicon


Bill

[dennis1573]

Hi Fraser, i increased the Spiral height to 0.9mm (so 3 layers at 0.3mm layer height) for you.
I did not test it, so be careful...
I tried it once, with the Spiral at the same height as the Chopperwheel frame (3mm)
but it was completely out of balance...
I have attached the .stl file.

Bill, I think my camera is fine, i use it without the Argus3 control board.
So no Iris control (Iris is fully open), and i have set contrast and brightness to Auto in the GUI.
But i just measured the current, it draws around 550mA at 8V and after a few seconds it drops to around 350mA.
And yes i wanted to highlight the "sun-safe feature", i would never do that with a Vox or A-Si or an old Pevicon camera.
I have also noticed, that the argus3 camera can see the sun through glass. But my A-Si and Vox cameras cant, i thought BST is only LWIR?
here is a video: https://youtu.be/hV0hQQB1D9Q

This might be slightly off topic, but i have a question regarding the Raytheon BST GUI.
I decompiled it, and it looks like there is another password.
It accepts "user" and "tech", but i cant see any difference.
There is a Menu in the GUI, which looks like it might allow me to mark bad pixels.
I see it with the decompiler, but there seems to be no way to get to it...
Maybe someone has an idea? I have a PalmIR250 with 12 bad pixels...
i have attached pictures of the menus, i cant access...

[Bill W]

Bill, I think my camera is fine, i use it without the Argus3 control board.
So no Iris control (Iris is fully open), and i have set contrast and brightness to Auto in the GUI.
But i just measured the current, it draws around 550mA at 8V and after a few seconds it drops to around 350mA.
And yes i wanted to highlight the "sun-safe feature", i would never do that with a Vox or A-Si or an old Pevicon camera.
I have also noticed, that the argus3 camera can see the sun through glass. But my A-Si and Vox cameras cant, i thought BST is only LWIR?
here is a video: https://youtu.be/hV0hQQB1D9Q

That power sounds about right, must just be the result of auto-gain that I am not used to seeing.

As for any MWIR sensititivy, it is not intentional.  The camera is designed for LWIR, however in comparison to an ASi / VOx:

The BST pixel is a simple 'black' absorber of radiation, the structures in ASi/VOx are tuned to the LWIR wavelengths
You have only got 'internal' lens coatings on the sensor and Argus3 lens which are broader than the durable / carbon ones used on an external surface.
May also depend on whether some windows have any extra coatings with IR properties


Bill

[Bill W]

I have also noticed, that the argus3 camera can see the sun through glass. But my A-Si and Vox cameras cant, i thought BST is only LWIR?
here is a video: https://youtu.be/hV0hQQB1D9Q

As for any MWIR sensititivy, it is not intentional.  The camera is designed for LWIR, however in comparison to an ASi / VOx:

The BST pixel is a simple 'black' absorber of radiation, the structures in ASi/VOx are tuned to the LWIR wavelengths
You have only got 'internal' lens coatings on the sensor and Argus3 lens which are broader than the durable / carbon ones used on an external surface.

Just tried this with a ULIS ASi based camera, and it too can see the sun through double glazing.  Highly attenuated of course and the spot temperature reads about 50°C.
That is with germanium optics and 8-14µm internal grade coatings.  Adding an external 'durable' coated window drops the spot temperature of the sun to 28°C, so that alone must be around a 70% loss.
With a hard carbon window, you see nothing.

A point to note is that the ULIS sensors are not filtered against 3-5µm and do have some response (10% or so) there.

Bill

[Fraser]

Very interesting news Bill  I mistakenly thought that Microbolometers were filtered for LWIR only. Any ability to see in the MWIR band could possibly be exploited using a MWIR lens in place of the LWIR type normally fitted. Maybe an area worthy of experimentation for those eager to have some form of MWIR capability ? 10% is better than nothing  Sadly MWIR lenses are uncommon and expensive.

Fraser

[Bill W]

Very interesting news Bill  I mistakenly thought that Microbolometers were filtered for LWIR only.

The majority are, if only by accident of the coatings used, and the likes of the ULIS Pico 384 used on the test above have a small response but hardly 'by design'.

ULIS did do trials with a broadband window, and I recall that some dies had a ~ 50% response in 3-5µm.
A bit about this in the SPIE papers that ULIS did early on - search for authors Tissot and Crastes.

Bill

[Bill W]

As noted in the teardown, the BST is a self-sufficient camera core, and the Argus3 chassis can be stripped of the fire camera extras and used as a basis for a smaller camera that offers much more user control thanks to the Raytheon software being 'out there'.

What follows below is taken from the reuse project documented here http://www.fire-tics.co.uk/project3/index.htm

The Argus 3 camera used the digital data from the Raytheon SECCA PCB, rather than the analogue output. However the analogue, and means to power the part-built camera, was provided to allow the core sub-assembly to be classed as a 'camera' for customs purposes.

These connections, and the fact that the BST core itself was designed for use in a simpler 'volts in - video out' stand alone camera such as the Raytheon Palm IR and vehicle vision products, means that a functional camera can be made solely with the Argus 3 detector PCB & the Raytheon parts to provide a 'volts in - video out' stand alone cameraor by using the 40 way connector with access to more controls via software and digital video data. The output in this case will the basic corrected core video and without the added graphics of the Argus3 camera.

The core fits inside a 'brick' of frontal area 125x184 mm, 70mm deep including the standard lens. The chopper diameter is 70mm and is fully enclosed within the frontal area.

[Bill W]

An extended guide to the relevant points on the detector PCB, before moving on to the minor hardware mods needed to get it going.

PCB functions, clockwise from the top

    Peltier override, allowed the EEV circuits to interrupt the peltier if the camera got too hot, also to assist startup.
    BST sensor
    Test points on DC control voltages for the BST core gain & Offset
    RS-232 connection for direct control of BST core image processing
    The 'BST DAC' sets up analogue voltages to control the core video gain and offset. Control by SPI from EEV boards via 40 way connector
    JTAG header for PLD
    The detector PCB PLD controls the iris in the lens by sampling the digital video stream and also shift logic to rephase the chopper wheel to match the mechanical arrangement of the Argus3. It has the digital data available (for iris control) so could be repurposed
    Testpoints on the 8 bit video data bus (upper bits of 10 from the core)
    40 way connector, 0.1" pitch with all necessary signals present, so can be a single connection
    R66, a link to allow the 5V regulator to receive input power
    5V regulator
    6 way 0.1" test connector with iris test, power in and video out.
    Lens connector, used for iris drive and limiting
    Iris drive, H bridge style pulsed power for the iris motor
    Chopper wheel sensor, detects the edge notch in the chopper wheel to allow it oto be synced to the video timing. As it is not the same angle as in the Raytheon basic design, the PLD has to phase shift the pulse

It should also be noted that a large number of test points exist, all labelled with the signal names, hopefully fairly obvious.


Bill

[Lambda]

Thank you Bill for this dense complement about the Argus 3 system.

One question (among others which will come... )

Would it be possible to substitute the whole bloc of the genuine motorized (Iris) lens by another optical bloc being manually focused, without any specific iris, a bit like in this version i dared to modify from your original diagram?

The fact that there would be no more iris actuator, or in other word, that the terminals from the Iris controller would be unplugged, would it create some management issues for the SECCA, and consequently for the Core Video Output, because of a lack of signal, no more pulled current detected, absence of any kind of feedback signal? Would it render the whole system inoperant?

I guess without iris, for fire environment, it would be a big issue concerning the dynamic range of the camera, but for using in normal ambient environment, night landscape and night wildlife monitoring ?

Thank you for your input on these points....

Cheers.

Stéphane

[Bill W]

Thank you Bill for this dense complement about the Argus 3 system.

One question (among others which will come... )

Would it be possible to substitute the whole bloc of the genuine motorized (Iris) lens by another optical bloc being anually focused, without any specifci Iris, a bit like in this version from your original diagram?

No problem at all.  Works fine with the lens unplugged, all that would happen is the drive would be trying to open or close all the time, none of it goes back to the SECCA (= Raytheon control board) it is all in the PLD.
If you had the Argus3 control board attached and were using that video, you would get a warning triangle graphic as it would think the iris was stuck.

As you suspect though, dynamic range would be limited but the SECCA AGC could be made available. I don't think Cadillac cameras had an iris

regards
Bill

[Bill W]

An extended guide to the relevant points on the detector PCB, before moving on to the minor hardware mods needed to get it going.

The only dependency for the 'core' on the rest of the camera is that the 5V logic on the EEV detector board is powered from the 10V supply in the rest of the camera (mainly for the LCD).
Hence my highlighting the 5V regulator in the image above.  Fortunately 'someone'  put in a link to solve this problem.  R66 connects 'power in' +ve to the 5V regulator input.  Downside is that you lose the bottom end of the input range, you need >7.5V for the regulator to be happy, and also need to keep below 10V for the core to be happy (in case you have any dodgy tantalums on the Raytheon SECCA).

Without the 5V, no chopper pulse from the PLD although you could rewire that directly if low voltage operation is vital.

Next step is dealing with the DC control voltages for the SECCA video gain and offset.  The default condition through the DAC's without the rest of the camera is that of 'DC control' and the 'DC control' is set to zero.
By far the easist answer is hooking up the RS-232 and running the Raytheon software to take control of the core and make it 'computer' controlled, and this can be saved so that it starts up that way.  All this was a hang over from the original 'analogue' core where this was the only way to set gain and offset.

The software is linked in this thread, down on post #23
https://www.eevblog.com/forum/thermal-imaging/the-story-of-a-radiance-1-camera-and-frasers-quest-to-find-information-on-it/
with thanks to the contributor, but you'll probably need a WinXP machine with a serial port.

I'd have to add the alternative of keeping with the DC control, 5V on the two selects would make the SECCA go to 'auto' or putting variable DC on the 'os' and 'gn' lines give you DC control.  All would need battering the DAC into submission, again handy resistors make this easy.

• R49 - Offset enable
• R50 - Gain enable
• R51 - Gain DC level
• R52 - Offset DC level

C30 & C25 have the 5V DC from the SECCA to use for pots / links rather than the PCB 5V

Bill

[Lambda]

Hello.

Thank you Bill for you replies.

I am a bit ashamed to ask you a so trivial question for you, but i need to clarify this for my understanding..

Did i assume correctly the pinout of the 6 ways connector used for a basic Video-out/power-in basic mode ( see the extract i annotated, coming from your website http://www.fire-tics.co.uk/project3/index.htm ) ?

Thank you!

Best regards.

Stéphane

[Bill W]

Hello.

Thank you Bill for you replies.

I am a bit ashamed to ask you a so trivial question for you, but i need to clarify this for my understanding..

Did i assume correctly the pinout of the 6 ways connector used for a basic Video-out/power-in basic mode ( see the extract i annotated, coming from your website http://www.fire-tics.co.uk/project3/index.htm ) ?

Thank you!

Best regards.

Stéphane

No, the other way round.  Go by the legend text.  I'll go fix that page to deal with narrow screens.

Might as well add the following about power.  The boards DO NOT include reverse polarity or spike protection. Protection should be considered if the core is not powered from a clean DC supply.
A number of 'DIY' conversions to vehicle use have failed as car alternator spikes will kill the BST core, mainly through poorly specified tantalum capacitors. At startup there is a power surge at 10W until the sensor peltier control has stabilised, one reason there is a peltier interrupt on Argus3 as noted in another thread.
Once in normal running, power draw drops to around 3.5W.

[Lambda]

Ok Bill. 

It is crystal clear!

Thank you.

Stéphane

[Bill W]

The relevant bits around the DAC for video control.  I can go into more about the DAC, but suspect anyone doing this will go the RS-232 route.

Again the legend has the directions indicated.

[Bill W]

The other way to connect is the 40 way on the bottom of the board.  This has all the connections needed, and a fair few others that might be of interest as there is access to the digital video and also the SPI (analogue gain DAC's and PLD).

Note the presence of '10V' (pin 11) and '5V' (pin 40) as well as '+VE' (pins 1/3/5), so a few options to sort out the on-board 5V supply issue.  The '10V' is only there for the 5V regulator so does not need to be 10V.
So, a +9V on 1/3/5/11 will be fine, or 5V on 1/3/5/40, but watch the current draw at low input.

[Lambda]

Hello.

Bill, when i read gain your disclosure in your page project, i have still some incertitudes in my comprehension (  ), concerning a proper way to settle the core in a "Power In - Video Out" mode.

I have the feeling that the pinout of the 6 ways connector used for a basic Video-out/power-in basic mode has to be used, as you clearly explained here, and in your website. But i have also understood that the pin 11 has also to be fed by a DC supply providing 7.5V minimum (or the pin 40, directly with 5V).

So for the basic mode "Power In - Video Out":

6 ways connectors:
- Vin (0/+) (5-9 V)
- Video out (0/V)

AND ()

40 ways connector:
- pin 11: Vin (7.5V mini)
OR
- Pin 40: Vin (5V)

Is it correct?

Thank you again for this additional clarification, and sorry (also again) for my slowness for understanding...

Best regards.

Stéphane

[Bill W]

Hello.

Bill, when i read gain your disclosure in your page project, i have still some incertitudes in my comprehension (  ), concerning a proper way to settle the core in a "Power In - Video Out" mode.

I have the feeling that the pinout of the 6 ways connector used for a basic Video-out/power-in basic mode has to be used, as you clearly explained here, and in your website. But i have also understood that the pin 11 has also to be fed by a DC supply providing 7.5V minimum (or the pin 40, directly with 5V).

So for the basic mode "Power In - Video Out":

6 ways connectors:
- Vin (0/+) (5-9 V)
- Video out (0/V)

AND ()

40 ways connector:
- pin 11: Vin (7.5V mini)
OR
- Pin 40: Vin (5V)

Is it correct?

Thank you again for this additional clarification, and sorry (also again) for my slowness for understanding...

Best regards.

Stéphane

The PCB 5V needs a supply.  There are several ways to do it, it can be all be via the 40 way (for people going that route) or

To ONLY use the 6 way:

6 ways connectors:
- Vin (0/+) (7.5-10 V)  *** NOTE the 7.5V minimum if going this route
- Video out (0/V)
- Fit R66

R66 joins the Vin +ve to the '10V' input at pin 11, and all the 10V is only there to power the 5V regulator.
In the drawing, 'Power' is the Vin power.

Obviously this is only OK once there is no 'motherboard' connected, or it can all get a bit wierd.

The reason, Argus3 was designed to run from a Sony camcorder battery of 5 x NiMH so not enough volts for a 5V supply.  Easier and no worse in efficiency to tag the trivial load of the 5V from the '10V' needed for the LCD display than to have a Vin - 5V switching converter.

regards
Bill

[Lambda]

Ok Bill.

When you indicate " - Fit R66 ".

Do you mean that a resistor has (also) to be settled on the PCB, between the two visible little silver pads (surrounded by the purple cirlcle)? This resistor is not already present?

If a resistor has to be settled, what is the value required for this resistor ?

Thank you for your patience.... 

I will try to do a proper scheme for representing a practical configuration with an external DC power supply and a video screen....

I keep on doing my homework....

Regards.

Stéphane

[Bill W]

Ok Bill.

When you indicate " - Fit R66 ".

Do you mean that a resistor has (also) to be settled on the PCB, between the two visible little silver pads (surrounded by the purple cirlcle)? This resistor is not already present?

If a resistor has to be settled, what is the value required for this resistor ?

Thank you for your patience.... 

I will try to do a proper scheme for representing a practical configuration with an external DC power supply and a video screen....

I keep on doing my homework....

Regards.

Stéphane

Hi Stephane,

R66 can be a 0R0 or simply a wire link. (Will update website, thanks)

R66 is not fitted on the normal camera build of the PCB.  When I am making up cores for resale as 'volt-in video-out' I have to fit R66 as part of the conversion.

regards
Bill

[Lambda]

Bill, ...

As a boomerang i am coming back for a new question.... 

Concerning the chopper used in the Argus 3, it seems that:

- On one hand, it is made from a "full" frame with an opaque helicoidal shape, the remaining clear surface out of the helicoidal shape being "translucide".... (left chopper in the photo below (extraction from your website)
- On the other hand, you propose as spare part, an individual chopper configured to be used with Argus 2/3, but this one is made with the same opaque helicoidal shape, the remaining surface being simply empty (no translucide film, nothing, empty....)... (right chopper in the photo below (extraction from your website).


Why is there this difference (on one hand, clear aperture of the chopper being a translucide film, on the other hand, empty space...) between these two choppers...

As a small remark, i would imagine that the second version (clear empty aperture) would let pass through more LWIR light and allow to obtain more signal, with also a more sharp "on/off" alternance ?

In advance, thank you for your lights on this specific points (Fraser i am sure you would have also very interesting input also about such specificities...)

Cheers.

Stéphane

[Bill W]

The 'cut out' chopper was a very early version, I am not aware of any measureable difference in use, although as you say there must be some.
As dynamic range was a limit on BST for general use, maybe the loss was not considered a problem


I stayed with that image so it is obvious which pattern I have as spares - ie not the narrow spiral ones for Cadillac vehicle vision cameras.  In fact all my spares (now) are full film ones

Some people have bought them for Cadillacs and did not take me up on the return refund that I offered, so they must have been at least partly useable.

regards
Bill

[Lambda]

Hello,

Thank you Bill. Ok for this additional information for the chopper.

I dare to ask one more thing (the last? i can not promise...  ) .
I was again studying your website:

the part concerning the video control of the core of the Argus 3

http://www.fire-tics.co.uk/project3/index.htm

If i summarize well (not sure....), i understand the following:

- For people who wants to buy one of your spare core, you would reset the core for setting it in a kind of "fixed or automatic brightness and contrast control", which would allow to use the core in a stand-alone mode by itself, independently of any external informatic interface, for a DIY project ("Videoput/power in").
I suppose that for preparing the core in this sense, you will proceed following the idea given in the green frame (in combination with your notice to be read in the purple frame.

But,

- I see that there would be also a possibility to acquire a kind of "manual" control of the brightness and contrast by using potentiometers to be added.
such configuration allowing to obtain this control without using the RS232 port and any computer, external microcontroller, whatever...
See your teaching coming from the red underlined text in combination with the blue underlined text and frame.

I would like to know a bit more on this second point:

- what do you concretely mean by:

" Disconnet the DAC and set up DC control level externally via pots. See test points "gn" and "os". "

What i can imagine is that the idea is to substitute the analog signals normally delivered by the DAC (fed by the digital control signals produced by the computer), by analog voltages directly applied to specific input on the PCB of the core, while bypassing/disabling the DAC.... But:

- at which points (something related to "gn" and "os" i guess ? (one pot between "gn" and ground, one other pot between "os" and ground, other configurations?)
- what value of potentioneters, which voltage span, origin?

Sorry again for all these questions, but as you guess, i consider to contact you for buying one of your core in the "near future"..... i try to have a basic but correct understanding for my next project and would like to do things properly....

Thank you again.

Best regards.

Stéphane

[Bill W]

Hello,

Thank you Bill. Ok for this additional information for the chopper.

What i can imagine is that the idea is to substitute the analog signals normally delivered by the DAC (fed by the digital control signals produced by the computer), by analog voltages directly applied to specific input on the PCB of the core, while bypassing/disabling the DAC.... But:
-

I was going to avoid the subject and only explore it when I get round to writing up about the Argus2 cores - which are analogue only and have some extra pads to make it easier.

However, since you ask...

The DAC is controlled by the Argus Control board over SPI, not the external computer on the BST RS-232. 

The control voltage is 0 - 5V, and there is a 5V supplied from the SECCA for this.  It is used on the MAX510 DAC as the reference input.
The 4 analogue control lines simply go to an ADC on the SECCA, so the selects can simply be 0R0 links while for the controls Raytheon recommend a 10k pot, but may be better if done as a chain (10k - 10k pot - 10k) as there is not much use at the far ends.

Name	Function	Operation
ABC ON / ENOS	Enable offset control as manual or automatic	0V = manual, NC or 5V = Auto
ABC SET / OSDC	DC offset control level when under manual control	0 - 5V
GNMODE / ENGN	Enable gain control as manual or automatic	0V = manual, NC or 5V = Auto
MNGN / GNDC	DC gain control level when under manual control	0 - 5V

regards
Bill

[Lambda]

Ok Bill, thank you for your disclosure.

I tried to do a kind of summarized scheme, based on one of your general photo of the PCB, with figuring how i would settle it, following your explanations, from the beginning, for a stand alone project, with gain and contrast manual control.
I have nevertheless difficulties to localise the ABC ON/ENOS and GNMODE/ENGN lines or terminals, and i guess i need to ground them (0V) for manual selection.

(for the voltage dividers, on a practical point of view i could use a unique DC source (the red one [7.5-9]V) and just adapting the ratio between the pots and hill-resistors for reaching a max of 5V for "gn" and "os"? i suppose there is little if not almost no current drawn in "gn" and "os" input ?)

In advance, thank you for correcting/completing, if you wish, my attempt.

(For the scheme and its readability, i just roughly reproduce the position of the terminal/input "gn" and "os", hidden behind the chopper...)

Regards.

Stéphane

[Bill W]

I tried to do a kind of summarized scheme, based on one of your general photo of the PCB, with figuring how i would settle it, following your explanations, from the beginning, for a stand alone project, with gain and contrast manual control.
I have nevertheless difficulties to localise the ABC ON/ENOS and GNMODE/ENGN lines or terminals, and i guess i need to ground them (0V) for manual selection.

(for the voltage dividers, on a practical point of view i could use a unique DC source (the red one [7.5-9]V) and just adapting the ratio between the pots and hill-resistors for reaching a max of 5V for "gn" and "os"? i suppose there is little if not almost no current drawn in "gn" and "os" input ?)

In advance, thank you for correcting/completing, if you wish, my attempt.

(For the scheme and its readability, i just roughly reproduce the position of the terminal/input "gn" and "os", hidden behind the chopper...)

Regards.

Stéphane

I would recommend using the 5V the SECCA provides'+5CONT' I think it is called, but may not be labelled up.  There may have been a reason that Raytheon said it should be used, like power sequencing.

I do not have the circuit handy just now but from the PCB image:
https://www.eevblog.com/forum/thermal-imaging/argus-3-(bst)-teardown-and-repairs/?action=dlattach;attach=1212055

Pin 4 of MAX510 is the reference, so C26/C30 have the '+5VCONT' on them

There are series resistors for the 4 voltages are R49/R50/R51/R52 and decoupling for OS and GN (C23 / C24).
The ENOS / ENGN are the other two channels from the MAX510 that are not OS and GN.

I will look out the circuit and post back (sometime)

regards
Bill

[Lambda]

Hello.

Just a short passage for keeping a trace in this small "log-book", following your last reply, Bill.

in the following scheme, i think i have at least spotted the 5V ref provided on pin 4 of the MAX510 by the SECCA, and a ground line GND.
Added also diagrams and pinout of a MAX510AEWE collected from the net...

I have now to figure out where are exactely the ABC ON/ENOS and the GNMODE/ENGN, for switching them (by grounding them if i understood properly...) in manual control of gain and offset.

I am focusing on your infos here, for this last point:

There are series resistors for the 4 voltages are R49/R50/R51/R52 and decoupling for OS and GN (C23 / C24).
The ENOS / ENGN are the other two channels from the MAX510 that are not OS and GN.

I will look out the circuit and post back (sometime)

Investigation is going on.

Thank you.

Best regards.

Stéphane

[Fraser]

Lambda,

Thank you for documenting your work so well. I am sure your posts will be very helpful to others in the future 
It is so nice to see someone giving back to this community after asking for help 

Fraser

[Lambda]

Hello Fraser.

Honestly    , this is the least i can do for the community and you guys who are so helpful and good willing.

Here, I just try to re-draft a bit on my own "visual" manner the teaching of Bill.

Generally speaking, I like the idea to collect/share practical infos in a forum and to see it as a wonderful interactive archive or open "log-book"....

Best regards.

Stéphane

[Ultrapurple]

I second what Fraser said about giving back to the community (and also saying thanks to the people who help you along the way).

I expect I will find this thread useful in the future. I have a working Argus 3 sitting in my shed that I intend to 'have a go' at in due course; it's highly likely that I'll refer back here. Thanks all (and especially to Bill for sharing his unique insight).

[Bill W]

Honestly    , this is the least i can do for the community and you guys who are so helpful and good willing.
Here, I just try to re-draft a bit on my own "visual" manner the teaching of Bill.

Also thanks for the proof reading of the forum posts & my website so I know to fill in the bits I have skipped over too lightly.

Bill

[Lambda]

Bill, i can imagine the time you invested in your website for documenting it....

Honestly, i think this is the only source in this specific field and product (on my knowledge) of practical informations reachable for public on a worldwide level...
In advance, thank you for your coming update....

I keep on digging in the guts of this "beast". i tried to imagine two configurations which would allow to control manually the gain and offset/contrast of the video delivered by the core.

- First "hypothesis", see the first scheme.
- Second "hypothesis", see the second scheme.

Here is also the datasheet for the DAC MAX510 (AEWE) from MAXIM (there is the 509 and 510, the document has to be scrolled for reaching the pinout part corresponding to 509 and 510 in correspondance...)

https://nl.mouser.com/datasheet/2/256/MAX509-MAX510-1292568.pdf

For the first hypothesis, i am a bit concern if i cut the analog DAC A and B output (pins 1 and 2) without more precaution: i do not know if there is not somewhere a kind of feedback send back to the SECCA... cutting pin 1 and 2 ("floating" them) will not induce some messing with the SECCA?

I have the impression that the second hypothesis is closer from what you explained to us, Bill, till now.

In both "hypothesis", the configuration of the pin 4 in relation with the divider and "os", "gn" stays the same...
Please, just tell me your thoughts and if i drive on a wrong path....

Thank you again.

Best regards.

Stéphane

[Bill W]

Option 1 will work, but is excessively destructive.  Just remove your choice of resistor to render that DAC output ineffective:
R49 - Offset enable
R50 - Gain enable
R51 - Gain DC level
R52 - Offset DC level
The pad at the SECCA end of the resistor can then be used to inject the required DC.  See attachment

Option 2 is the same DAC condition as you get with no EEV control board in place, so makes no difference.

It will be clearer once I have posted the circuit around the DAC, and the Argus2 equivalent, so maybe do not worry too much for now.

Bill

[Lambda]

Ok Bill, i store it preciously. 

While waiting your update, i stay tune, no hurry.

Just for the discussion, why do you consider the "option 1" I proposed excessively destructive?
Because, at the end, it consists just in cutting pin 1 and 2 (i mean: cutting the PCB terminal tracks/paths connected respectively to pin 1 and 2).

In your way, you have also to act on the hardware by physically extracting resistors (unwelding/cutting)....

Thank you for your comment on this point.

Best regards.

Stéphane

[Bill W]

Yes, they are electrically equivalent, but the resistors are easier to put back than it would be to uncut tracks / pins if you change your mind, that's all.


Bill

[Bill W]

Circuit for the DAC bit attached below

Bill

[Lambda]

 

Thank you Bill !! Now the mist is gone!

Here is a summary about all your explanations (remarks are "copy and paste" from your remarks from previous posts):

Best regards and thank you again!

Best regards.

Stéphane

[Logan]

Hi, thanks a lot for sharing your design file!
I now get a few printed, but my s300a's chopper wheel is glued to the shaft (instead of the screw in some other designs). How can I remove it safely? I'm afraid just pulling it out may damage the motor bearing...

[dalittle]

Bill,
It was such a pleasure to read your post on the Argus 3.  I haven’t heard the term SECCA in over a decade! My goodness.

At ISG we also designed our own FPA board so it would fit in a smaller enclosure. The Raytheon one was huge. However, we didn’t have Raytheon put the FPA on our board, we did it ourselves (saves on the air-miles.)

Most people will not know this albeit Bill probably does: The early 200 series BSTs had Peltiers set to stabilize at 22C while the 300 series BSTs stabilized at (I think it was) 35C and thus that core used more power most of the time.

The iris assemblies on both the EEV units and ISG units were kinda a throwback to the old PEV days. And they were unreliable as hell.  In later PEV variants, ISG removed half the leaves and it helped. Then in BST, changed to a cat-eye design that never ever failed.  It was good enough for firefighting application.

So, Raytheon killed the BST product line because they had a new program to replace it – and I can’t for the life of me remember the name of program – it wasn’t the ASI, it was something else ferroelectric also.  Bill may recall.  In any event, the new technology never came out of engineering at Raytheon.

Raytheon used to bump-bond the pixels to the readout and in the early days, I understand they lost half of them to yield. But over time, and towards the end, they really did perfect that process and yields were in the very high 90’s I was told.  And, in typical fashion, when everything was going great, they killed the program.  Chris Bade was the RTI boss man at the time. We did not agree with their decision. Seems bigger companies have a cancer of bringing people in from outside the infrared space to hold very key positions and they end-up making really bad decisions, then they move on to something else leaving the wreckage behind.

Off topic comment: I was in the UK when 9-11 happened. As I was to leave the following day, I was stuck at the Gatwick Hilton with a Raytheon guy and had an additional 3 days or so because all the flights were cancelled.  Raytheon and I would take the train in from Gatwick and go to a pub on Queens Gate in South Ken called Kavanaugh’s.  We would be wearing jeans and trainers. Every time we walked in, patrons would look at us – ah, Americans? Let me buy you a pint! And we would sit there for hours talking about what had just happened.  The hospitality was bar-none the best I’ve ever experienced.  Mind you, we were in Central London so… these same guys were the ones running you over in the Tube station if you were even the least bit unsure!  Really nice blokes during very unusual times.  Our two countries really do share a lot of common values (although our common language doesn’t seem to be that common.)

Thanks again!

[Bill W]

David,

I was not aware of a 'low temperature' BST, but then ISG were into BST sooner than EEV as you neither had the profit margins that in-house Pevicons gave EEV nor had to go on a year or so wild goose chase after being told to use the GMEO sensor (the 256x128 sucessor to the Cairns Iris PZT types ex Plessey) as that was GEC-Marconi in house.

Low temperature makes sense if your intended use was outdoors at night.

The sucessor chopped sensor from Raytheon was going to be the 'TFFE' thin film ferroelectric.  As you say it never saw the light of day.  As well as the competing ASi (would be the AS3500 at the time) another problem was the EU lead-free solder directive.  Until we sat them down and read it out to them they did not believe it applied to anything other than consumer equipment.

There was also the issues around export licensing which was getting worse each new annual order.  That was why Argus had sensors fitted at Raytheon, it meant we imported 'cameras' not 'sensors'.  Yes the PCB crossed the atlantic two times (or 3 if the customer was MSA USA), but the Argus2 shutter motor went across 4 or 5 times.
Made in Switzerland
Raytheon insisted on selling them in the kit to get pricing - so over to USA
Over to UK to get assembled
Back to USA for the sensor fitting
Back to UK to build camera !



regards
Bill

[Logan]

Hi, thanks a lot for sharing your design file!
I now get a few printed, but my s300a's chopper wheel is glued to the shaft (instead of the screw in some other designs). How can I remove it safely? I'm afraid just pulling it out may damage the motor bearing...

Okay I removed the glue by screwdriver...
I just made a modified version of the file, attached. Rename the ".txt" to ".stl" after download.
The total thickness is reduced to 2mm, the "film" thickness is 0.6mm.
Reason for this is, sometimes the thin "film" is not perfectly flat, it will bend towards outside, together with the total 3mm thickness, I cannot avoid it scratching other parts.
I tried Blender for the first time, just because this task...
I also wanted to center the "film", to make it not start from one side, but the polygon is fused together to the frame, so I haven't success yet.
It would be really nice to balance the weight, but I don't know how to do it.

[dennis1573]

Hi Logan,

i have printed a few of these, and never had problems with warping/bending.
If you have a heated printbed, make sure its completely cooled down to room temperature before you remove it.
I dont think its a good idea, to center the Spiral. That way, it wont be in contact with the printbed and you need supports...
I think you should print it in two parts, 1st part the Wheel with the Spiral on the bottomside and the 2nd part just the Wheel then you glue the 2 halves together.
I have attached the Chopperwheel with the Spiral centered (2mm Frame 0.6mm Spiral) and the same in 2 parts so you wouldnt need supports.
I cant help you with balancing, i always printed it with 0.3mm for the Spiral so that was never needed...

[Logan]

Thanks a lot dennis!

[Logan]

Well I tested the solid version.
The dynamic range is really bad, and there's NO improved sensitivity as I hoped.
Also there's fixed pattern noise(?!) and uneven brightness with solid chopper.
No wonder why Raytheon just choose the dotted film version...

[Bill W]

The uneven brightness might be a slightly out of phase due to the greater weight of the solid chopper.
Check if the detection pulse is in the same place with each.

It should be the same delay after video field pulse.  On Argus3 there is a significant delay between them as we moved the chopper sensor from the Raytheon expected location.
If you can get at 'CHFB' signal that might be zero delay to video - I'd need to check

Bill

[Gareth79]

Seeing this thread prompted me to look at the 2x Argus 3s I have, I thought both I had needed repairs, but seems one is ok.

I bought 3x of them a few years ago, one was in perfect order and I resold it (for more than I paid for all 3).  One had a dead screen which I replaced with an LCD monitor, the other used to take quite a while to warm up.

I just powered them up though (connecting directly to the contacts) and one seems fine. The other has a permanently grey image (even after leaving it several minutes), I think this is one I left on overnight and which had the grey image when I returned (oops!), is that likely to have damaged something?  I have stripped it down and am awaiting a Nintendo screwdriver to be able to remove the control board, with a view to making a more compact device. (A friend thinks it might be an RS System Zero screw?)

Pic of the working one!

[Bill W]

I just powered them up though (connecting directly to the contacts) and one seems fine. The other has a permanently grey image (even after leaving it several minutes), I think this is one I left on overnight and which had the grey image when I returned (oops!), is that likely to have damaged something?  I have stripped it down and am awaiting a Nintendo screwdriver to be able to remove the control board, with a view to making a more compact device. (A friend thinks it might be an RS System Zero screw?)

Yes, they are RS 'tamperproof' types.  I'll advise the RS parts when I can.

Leaving on overnight should not be a problem, although long term use was never a consideration in design.  If you can quantify 'grey' it might help.
A noisy grey image suggests all the electronics is working and the cause is more a closed iris, which would also generate the 'warning triangle of doom'

A flat noise free grey image would suggest zero gain is being applied.  Then you look to the gain biases and similar.

A blank (ie video black) image can have a lot more causes. 

A scope on the BNC out will show up which if it is not obvious.

Note that removing the control board also removes all the gain / offset leaving the core set to manual control, no input' which is zero gain and offset.  You can use the information in the tear-up thread / fire-tics project to convert the stripped down core into manual mode.
http://www.fire-tics.co.uk/project3/index.htm

Bill

[Gareth79]

I just powered them up though (connecting directly to the contacts) and one seems fine. The other has a permanently grey image (even after leaving it several minutes), I think this is one I left on overnight and which had the grey image when I returned (oops!), is that likely to have damaged something?  I have stripped it down and am awaiting a Nintendo screwdriver to be able to remove the control board, with a view to making a more compact device. (A friend thinks it might be an RS System Zero screw?)

Yes, they are RS 'tamperproof' types.  I'll advise the RS parts when I can.

Thanks, I sent a pic to a local friend who has a set of those drivers so I may not need to wait for the Nintendo one to arrive even.

Leaving on overnight should not be a problem, although long term use was never a consideration in design.  If you can quantify 'grey' it might help.
A noisy grey image suggests all the electronics is working and the cause is more a closed iris, which would also generate the 'warning triangle of doom'

A flat noise free grey image would suggest zero gain is being applied.  Then you look to the gain biases and similar.

It's the proper video with overlays etc. but flat grey and no noise that I could see, it basically stays like the grey from startup and doesn't 'clear' to reveal the thermal image. The triangle didn't appear within several minutes, I have seen it on one of them before. I'll get it all hooked up later and check all the test points in detail.

Note that removing the control board also removes all the gain / offset leaving the core set to manual control, no input' which is zero gain and offset.  You can use the information in the tear-up thread / fire-tics project to convert the stripped down core into manual mode.
http://www.fire-tics.co.uk/project3/index.htm

I've already had a good look over that, very useful many thanks! I will put it all in a more compact box for sure,

When I'm done I can post you all the spare bits for your parts collection!

[Gareth79]

Minor update - the friend dropped over their RS System Zero tools and I have a solution early

[Gareth79]

Ok, I finally found time to have a futher look at the "grey screen" Argus 3.

I stripped it down and replace the power/video header, and then added the RS232 header, and bridged R66. I could connect fine using the configuration software, and figured out the controls, eg. changing to the lower speed (9,600 I think) and setting it to "Computer".  Basically whether the Auto or slider mode is set it just has the same solid image, with a hint of noise and banding (pic below).

I think stripped down the working camera I had and repeated it, to check I was doing it correctly, and indeed with that one I get the correct image (pic below).

Any suggestions welcome! I prodded a few test points but am not yet sure what to look for. I will have a look over the circuit diagrams. Thanks!