FNIRSI-1013D AS MUCH USE AS A CHOCOLATE FIREGUARD.

[pcprogrammer]

Hi George,

about the colors, when you bought the scope was it already like this or did it show the yellow and cyan traces on a dark background?

If so, this means some part of the system broke down causing this, but what broke down, that is of course the question.

Cheers,
Peter

[Gannet]

Good morning, Peter, I don't think the colors I have are what they used to be!
Additionally, although it appears to be working, the scope will often 'Switch off' and sometimes it will take one or two cycles of the on/off button for it to re-awake.
Hmm, maybe I do have an onboard fault after all.

Regards

George

[pcprogrammer]

Hi George,

with the problems recurring it indeed points to some defect. I have searched on goolge for inverse colors on LCD, but it did not give much to go on.

I have no idea if a power supply issue can cause a display to do what yours shows. Can you measure the voltages with a multi meter? Especially the -6.3V, 15.8V and the 10.3V.

It will be a process of exclusion to determine the root of the problem.

[Gannet]

Hi Peter, here's what I get with the voltage check.

16.12v
10.62v
-7.16v

I attached another screen shot, Did you notice that the upper part of my grid/graticule is missing

Cheers
George

[pcprogrammer]

Hi George,

these voltages are within range of what is maximally allowed going by the datasheet I found for a similar panel.

Did not notice that the grid was missing in the upper half. Start to think that the display is the problem here. I wonder if you see a large current drop when you boot the scope without the display connected.

I bought this display and tested it with my scope. https://nl.aliexpress.com/item/32693491775.html I expect yours to be compatible with it. Maybe worth a try.

Don't know how the older model is constructed, but replacing it in the newer model is a bit tricky since they used double sided tape to attach it to the touch panel.
Someone used special wire to cut it loose in his scope. It is mentioned somewhere in the FNIRSI-1013D thread.

Regards,
Peter

[Gannet]

I’m willing to give the display a try Peter, so I’ll order one up, what’s bothering me that the scope is sometimes very difficult to ‘turn on’ and often turns off at random.  So there’s a bigger issue somewhere?

Praps I was a bit quick on celebrating.

Cheers George

[pcprogrammer]

Hi George,

the turning of could be a thermal protection of the main regulator, since it is drawing ~30% more current. The difficulty in turning it on might be related and depends on when it happens.

As you can see in the schematic, the power switch only controls an enable to the SPX29302T5, which makes the latter the actual power on part. It could have problems turning on when there is too much initial current being drawn. But this is not my field of expertise.

Did you check the other voltages in the scope, like the 1.2V, 2.5V, 3V and of course the 3.3V? Another one is VREF which should be ~1.25V.

Regards,
Peter

[Gannet]

Where are the schematics Peter?

I didn’t check those other voltages yet

Cheers

George

[Gannet]

Sorry Peter, belay the last. I have them so I'll check all voltages and get back to you.

Cheers

George

[pcprogrammer]

Where are the schematics Peter?

I didn’t check those other voltages yet

Hi George,

had other things to do today, but going by your next post you found them. (The link was in my first post in this thread )

Cheers,
Peter

[Gannet]

That's fine Peter, I found loads of other info too. You say check the voltages, my goodness I can't even see the pins.  A breakout board of some kind would indeed help!
I looked at the file containing all the parts on AliExpress, some interesting stuff there I see. any particular item you'd recommend?

I have noticed that when the scope shuts down, well it doesn't, all that seems to be happening is that the display goes blank.

Is there a silk screen overlay anywhere with component Id's and locations?

Thanks

George

[pcprogrammer]

Hi George,

  I have the same problem. Need a microscope to work on these things.

About the goodies on Aliexpress, it depends on your hobby. I play around with microcontrollers and well scopes, and for that the things like a CH341 programmer or a ST-Link are very handy. But availability is troublesome at the moment causing the prices to be way to high.

I will mark the measuring points for you on one of the photos I have, because there is no overlay with component numbers.

About the shutdown the 3V3 should go down to 0, but there is a small delay to allow the MCU to write settings to flash (original) or the SD card (mine)

Regards,

Peter

Edit: Attached the power supply part with voltages mentioned. VREF is not 1.25V but it is for measuring the battery level with the MCU, so it varies and is not to important. The 3V is missing on this picture, so another one is coming.

You might have to download the second image and zoom in to read the text.

[Gannet]

Many thanks for the Voltage check points.

All voltages are within +0 and -160mv Peter, and with the display blank, you guessed it, all voltages are just the same, that's pointing to a bad display I guess, what do you think.

I have a display on order with a message saying 'dispatched'

Cheers

George

[pcprogrammer]

You are welcome. Happy to help.

Did you check the current when the display is disconnected?

I'm no expert on displays and have no idea if what yours shows is some typical failure behavior. Guess it is wait until the new one arrives to see if it is the actual culprit. 

Cheers,
Peter

[Gannet]

Hi Peter, I return with not so good results,
Trying to make sense of the display's that I'm getting and most appear gibberish.
I fear that there is a great deal more wrong with the scope than the display, in fact it may not be the display that is at fault after all. The washed-out colors etc could well be due to something other.
I have attached a pic of the waveform from the test point on the scope.

Maybe I should just bung it in the post and give you something to play with whilst you're not enjoying yourself. 

What do you think?

Cheers

George

[pcprogrammer]

Hi George,

which signal are you measuring? Not sure if probing the scope with itself works properly. There is the shifted ground issue to consider.

It would be an interesting object to play with

Did you order another display to test it with?

Cheers,
Peter

[Gannet]

Hi Peter, still waiting on the new display,
I'm probing the calibration input on the top of the scope; I assumed it was a square wave 1V test point.
However, I'm using a small square wave generator, have a look see at the results.

Cheers George

[pcprogrammer]

Hi George,

in both cases it seems to measure some 50Hz signal. Is that the mains frequency in your neck of the woods?

The calibration signal of the scope should be a 1KHz square, so if that is what you are connected to in the first picture you showed, the period time is 1ms, and your scope is set to 5ms/div and 20KSa/s, so it should show 5 periods per division, so yes something is wrong.

In your second picture it looks like it is picking up just the mains on an open probe.

Weird things happening indeed.

I just noticed that the pictures saved on the scope won't open on my Ubuntu machine. So have to do some digging of my own on why that is.

Regards,
Peter

[Gannet]

Hi Peter, yes I believe it’s pretty goosed, do yo fancy having a go of for me ?

I think it’s beyond my level, I’ll bet you a Haggis that the display is not the issue and if it’s not I’ll let you have it when it arrives

Yes we are on 50 hz in the Uk
Cheers

George.

[pcprogrammer]

Hi George,

You might be right that there are several issues with it than just the display. After you try the display when it arrives, and it does not solve the problem, I'm willing to give it a go. Having a working one and several other scopes besides it, at least gives the option of probing them to compare the signals and hopefully trace the problem.

I don't bet because I never win

Regards,
Peter

[Gannet]

Good idea Peter, I’ll let you know when the display arrives,

Keep safe

George

[BillyO]

I would argue that the chocolate fireguard is of far more use than the Fnirsi.

Let's say that fireguard was the firewall in a small airplane and you crash in the northwestern wilderness of Canada.  That chocolate firewall will serve to distract the grizzly bears while you make good your escape.  The most you could do with the Fnirsi is try to bat the bear about the head with it.  That would just annoy it.  Also, before the bears show up you could stuff some of that chocolate into a backpack for quick and tasty energy for your trek out of the woods.  The Fnirsi would just be deadweight and not the least bit nourishing and it probably tastes as badly as it works.

[Gannet]

[Gannet]

Hello Peter, the new display arrived and made no difference to my washed out colors.
I thought we were onto a winner but sadly no.
So if you are willing to have a go at it for me I'd be eternally grateful. You can have the new display as a Christmas gift. :-)

Let me know what you think.

Regards
George

[pcprogrammer]

Hi George,

that is disappointing. That makes me wonder what else can cause this. A side by side comparison might provide the answer.

I will send you a personal message to about sending it over.

Regards,
Peter