Getting a picture on a mini camcorder CRT

[Quantumplate]

I know, not very original, but for a bit of fun it appeals. I have the 1/2" crt from a broken Sony ccd-trv11e and worked out the ribbon cable connections thanks to Mr 12 volt vids. The manual for the camcorder says it is ntsc based and being in the UK i have pal gear (dvd player) going into it. So i thought i better get a converter box (shown in pic). But..i can't get a picture - I get a whitey screen whatever position the switch is in on the box.

All the videos on this I've seen, they just seem to provide a composite video signal and away they go. I don't understand much about old tv signals, specifically how the channel frequency o/p of the dvd player (in my case) would be matched to the fixed channel i/p of the viewfinder crt (whatever that is?). Are they always the same?

[wasedadoc]

The E at the end of Sony camcorder model names usually means it is a European model and is engineered for PAL.  If it is a PAL model, then despite the impression you are under, the viewfinder module is expecting 625/50 input and you should not be using a conversion to NTSC. Even so, either NTSC or PAL format video into the viewfinder module from a 210 or a 210E should give something visible on the tube.

The service manual can be downloaded from https://www.manualslib.com/download/1002030/Sony-Ccd-Trv11.html.  Use that to positively identify the video input point. Page 4-47 schematic.  Page 4-49 location D2 for physical placing of CN901.

Why are you using a cable with those Belling-Lee coax plugs?  The video signal from the DVD player into the viewfinder needs to be baseband not RF.  Your mention of "channel frequency o/p of the dvd player" and "fixed channel i/p of the viewfinder crt" is nonsense.

Edit: Fixed link to Service Manual.

[Quantumplate]

Even so, either NTSC or PAL format video into the viewfinder module from a 210 or a 210E should give something visible on the tube.

Why are you using a cable with those Belling-Lee coax plugs?  The video signal from the DVD player into the viewfinder needs to be baseband not RF.  Your mention of "channel frequency o/p of the dvd player" and "fixed channel i/p of the viewfinder crt" is nonsense.

Thanks for helping with my education on this. I've always skipped over analogue tv theory until now. And the only connectors i've ever used on the back of tvs/vcrs/dvds have been Scart connectors. 

What are the 210 and 210e you referred to? You lost me there.
I checked in the manual and it's pin 3 for video which i've wired up so that's all good. I did try inputting a signal without the converter box too when i initially hooked everything up two weeks ago.

I have that old coax cable there because i thought i would be plugging it into the rf out of an equally old vcr recorder. That didn't give a picture other than white so i moved on to the dvd player. Having soldered the pin to the wire I've left it like that and have to use adaptors to join it to a phono rca cable.
So i'm using the rca Video out socket from the dvd player.  Is that a baseband signal?
I thought it was rf out tuned to channel 36 for an analogue tv to decode, hence my utter confusion. Still confused actually as i don't see any other connection options from my dvd player. I've looked up baseband, but in all the analogue tv theory sections in my books the only signal in town is the rf composite video/audio signal, so i'm none the wiser yet.

 I do appreciate your efforts though!

[wasedadoc]

Sorry about the 210/210E.  I did of course mean TRV11/11E.  Don't know why I typed 210.

Yes composite video goes in on pin 3, the middle one.  And you need the ground side too on pin 2.

Video waveforms you see like https://en.wikipedia.org/wiki/Composite_video#/media/File:NTSC_Signal.png are always baseband.  DC to about 5MHz.

[Quantumplate]

Right, got it as far as what a tv baseband signal - one yet to be modulated on an rf carrier. So the yellow rca video out socket on the dvd player is CVBS or baseband. I should be getting a picture then, but i'm not. Maybe the viewfinder has a problem. Yikes, that 232 page service manual is the longest one i think I've ever seen!

[wasedadoc]

The viewfinder is relatively simple.  You have a raster on the screen so EHT and both H and V scans are OK.  The video input goes through one IC and then to a few transistors to develop the higher voltage video into the tube.  Easy to trace if you have a scope.

Video in on pin 11 of IC901.  Out (inverted) on pin 13. Q904 emitter is drive to CRT grid.  Points 3,4 and 6 (in circles) on schematic page 4-48. Waveforms on previous page.

If you do not have a scope, check voltages and do visual inspection.

[Quantumplate]

Thanks! My work space is obliterated by a repair job atm, but I'll get my scope on it in a few days and report back.

[Quantumplate]

Video in on pin 11 of IC901.  Out (inverted) on pin 13. Q904 emitter is drive to CRT grid.  Points 3,4 and 6 (in circles) on schematic page 4-48. Waveforms on previous page.

Okay, i made a new video-in lead buoyed with enthusiasm. Now, the measurements:  around the ball park figures in the SM were obtained. I also viewed the waveform on the scope. Looked ok as a composite waveforn to my untrained eye, but bear in mind it was only earlier in the day that i viewed a composite signal for the first time on my scop, just straight out the back of the DVD player. Pretty cool stuff!
Picture still not there of course. I'm wondering if the viewfinder, being designed for only black & white, cannot deal with colour signals. That would make sense to me in terms of saving money in production.

[wasedadoc]

Video in on pin 11 of IC901.  Out (inverted) on pin 13. Q904 emitter is drive to CRT grid.  Points 3,4 and 6 (in circles) on schematic page 4-48. Waveforms on previous page.

Okay, i made a new video-in lead buoyed with enthusiasm. Now, the measurements:  around the ball park figures in the SM were obtained. I also viewed the waveform on the scope. Looked ok as a composite waveforn to my untrained eye, but bear in mind it was only earlier in the day that i viewed a composite signal for the first time on my scop, just straight out the back of the DVD player. Pretty cool stuff!
Picture still not there of course. I'm wondering if the viewfinder, being designed for only black & white, cannot deal with colour signals. That would make sense to me in terms of saving money in production.

There is a remote possibility of colour signals affecting the sync separator in that chip but even if that happened I would still expect something to appear on the screen.  Have you looked at the signal on the emitter of that final transistor driving the CRT grid?

[Quantumplate]

Video in on pin 11 of IC901.  Out (inverted) on pin 13. Q904 emitter is drive to CRT grid.  Points 3,4 and 6 (in circles) on schematic page 4-48. Waveforms on previous page.

Okay, i made a new video-in lead buoyed with enthusiasm. Now, the measurements:  around the ball park figures in the SM were obtained. I also viewed the waveform on the scope. Looked ok as a composite waveforn to my untrained eye, but bear in mind it was only earlier in the day that i viewed a composite signal for the first time on my scop, just straight out the back of the DVD player. Pretty cool stuff!
Picture still not there of course. I'm wondering if the viewfinder, being designed for only black & white, cannot deal with colour signals. That would make sense to me in terms of saving money in production.

There is a remote possibility of colour signals affecting the sync separator in that chip but even if that happened I would still expect something to appear on the screen.  Have you looked at the signal on the emitter of that final transistor driving the CRT grid?

Yes, it's a healthy voltage and looks like the one pictured in the manual. It's like a composite minus the colour burst. One more thing i could try is rigging up my vcr with a black&white film showing. I know the pins out of the scart socket that i need. More faffing about! This is really bugging me though.

[wasedadoc]

A pound to a penny the colour signal is not the problem.

Does turning the brightness pot change the brightness?

[Quantumplate]

A pound to a penny the colour signal is not the problem.

Does turning the brightness pot change the brightness?

Yes, had a twiddle and doing its job.
 Not sure i can face the rigmarol of connecting the vcr...next step could be buying a b&w dvd and trying that. Recommendations welcome..

[AndyBeez]

If I remember my old camcorder 101, these miniature (cute) B&W monitors had a luminance (Y) signal input only. No color component (Cb/r) required. The luminance pin of a S-Video out might work - or scart pin 19 if avail.

Did you find the service manual and circuit diagrams for the TRV11e?

+ Otherwise, the syscon inside the camcorder is doing the heavy lifting sync wise.

[wasedadoc]

If I remember my old camcorder 101, these miniature (cute) B&W monitors had a luminance (Y) signal input only. No color component (Cb/r) required. The luminance pin of a S-Video out might work - or scart pin 19 if avail.

Did you find the service manual and circuit diagrams for the TRV11e?

+ Otherwise, the syscon inside the camcorder is doing the heavy lifting sync wise.

The schematic clearly shows  the monitor is self contained.  Needs only power and composite video.

[AndyBeez]

On the schematic, where on the system board does the 'composite' video signal originate? It may be tapped/mixed from the luminance channel that eventually feeds the video-out connector. Does your Sony service manual have any expected 'scope outputs for video?

[Quantumplate]

Hi Andy,
Thanks for joining in. I'm afraid as you can tell from reading this thread, this analogue tv thing is pretty new to me, fascinating though.
The link to the schematic has been posted earlier. I'm not qualified to answer your questions. I'll rig up the vcr in the morning and see what materialises then.

[wasedadoc]

The OP has confirmed video of nominal amplitude and shape s present at the output of the video driver to the grid of the CRT.  He has also stated there is a blank raster and its brightness can be changed by adjusting the brightness control.  The filament is also the CRT cathode.  It should be working. 

[vk6zgo]

The OP has confirmed video of nominal amplitude and shape s present at the output of the video driver to the grid of the CRT.  He has also stated there is a blank raster and its brightness can be changed by adjusting the brightness control.  The filament is also the CRT cathode.  It should be working. 

The next spot to look is at the actual grid pin of the CRT.

[wasedadoc]

The OP has confirmed video of nominal amplitude and shape s present at the output of the video driver to the grid of the CRT.  He has also stated there is a blank raster and its brightness can be changed by adjusting the brightness control.  The filament is also the CRT cathode.  It should be working. 

The next spot to look is at the actual grid pin of the CRT.

The brightness control adjusts the dc voltage at the output of the video driver and thence to the grid. The brightness control is working. Connection from PCB to grid must be OK.
Edit: See below.

[Quantumplate]

It should be working. 

Tried the vcr just now with a monochrome image. Nope, still just a whitewash! Worth a try. Well beginning to think it'll make a nice ornament - i believe James Dyson has one in his office.

[vk6zgo]

The OP has confirmed video of nominal amplitude and shape s present at the output of the video driver to the grid of the CRT.  He has also stated there is a blank raster and its brightness can be changed by adjusting the brightness control.  The filament is also the CRT cathode.  It should be working. 

The next spot to look is at the actual grid pin of the CRT.

The brightness control adjusts the dc voltage at the output of the video driver and thence to the grid. The brightness control is working. Connection from PCB to grid must be OK.

Can he cut the tube off with the brightness control?

This device is a bit weird---the smallest screened monitor I worked on, which would have had a display about the size of the viewfinder in mid 1990s Broadcast "shoulder held" news cameras, had a very tiny magnetically deflected Trinitron in it, complete with the normal 3 guns driven with R,G,B.

[wasedadoc]

Oops.  I've just looked at the schematic again and realised that the brightness control adjusts the cathode voltage, not the grid.  So yes, check what is actually at the grid connection on the tube base, W901 pin 1.

[Quantumplate]

Oops.  I've just looked at the schematic again and realised that the brightness control adjusts the cathode voltage, not the grid.  So yes, check what is actually at the grid connection on the tube base, W901 pin 1.

Just checked all the voltages on all the ic pins:
Pin1   0.75v  o dear...  Pin9   4.6v
Pin2   5.2v                     Pin10  gnd
Pin3   4.0v                     Pin11  2.4v
Pin4   gnd                      Pin12   5.0v
Pin5   0.3v                     Pin13    2.6v
Pin6   -0.4v  hmm..       Pin14   2.0v
Pin7   2.3v                     Pin15    2.0v
Pin8   5.0v                     Pin16    3.0v

i'll try and fathom what all that means.
I know it's not good though. Bought a camcorder labelled as parts only and sent with almost no packing,so i guess this is the result. 

[wasedadoc]

I would not be worried about those voltages on pins 1 and 6.  They relate to the vertical scan and unless you have a single bright horizontal line across an otherwise dark screen then there is definitely some vertical scan.  Some meters can show strange results when measuring voltages that are a mix of DC and AC.

Please connect your scope probe to pin 1 at the tube base and post a photo of the scope trace of the video there.

[coromonadalix]

bring back souvenirs,  played on one like this in the past, it could receive directly any ntsc signals     my mini tv  loll  i broke the tube