Mister Fab

At this point, my skills in electronics are just too low compared to yours, but I'll try to be good at drawing and to be the most accurate I can to finish to copy the circuit without any errors. It will take some time. I have nearly finished the back side. The component side is a bit tricky due to the tracks running under the large ICs.

@emmanuelf, sorry I missed your previous post. Are you talking about this ? https://www.retrogamingcables.co.uk/SYNC-SEPARATOR-CIRCUIT-BOARD-LM1881-COMPOSITE-SYNC-CSYNC-PCB-STRIPPER

Yes, I confirm. It should have been Q26

I just rechecked pin 4, I don't get any continuity signal with any pin of AV connector. I get a continuity signal between U29 pin 4 and C156 negative, and on the other side to C147 Sorry, I don't understand the green part I underlined in your comment.

I took a picture of each transistor, I think I didn't make a mistake about they're all npn. Aren't collector and base inverted on pnp?

Hi guys, I continued my work on the other side of the board. I didn't map the full board for now, but I'll continue to finish the full board, hoping it can be usefull to someone in the future. I will shrare the paint.net file when I'll have finished, it is easier to hide each layer when looking for something particular. I made a few modification on the component side to the tracks under the A/V connector, I found some errors while I started to map the back side. Let me know if you see some incoherences so I can correct them.

@ChildOfCv, there's no pnp transistor, only npn. F2N3904 F2N3906 MPSA13

Hi, I'll send tomorrow the pcb on both sides, I had some time today to draw it from the board on several layers with paint.net. Still in progress, but I hope it will help.

Here are the pics, I took quarter by quarter of the board. Tell me if you need more details.

Wow!! you impress me ChildOfCv!! Just to say, I practice electronics, but I have limited knowledge. But if you need any signal test, I have an oscilloscope, so if you tell me where to test I can give you all the results. I will take very detailed pictures this afternoon

Here are two hi resolution pics of the motherboard (91209 rev.B)

These are the two "official" wirings I have found on Colecovision.dk I checked my working cable (tested on a cathodic TV) with a ohmmeter, and here's what I got: Pin 4 and 5 (orange and black wires) are inverted on the DB15 side if I compare to the official wirings, and I can't understand how RGB blue and +12V can be inverted. I tested the voltage on scart pin 8, I get 12V as it should be. When I plug the cable to the OSSC, I get this on the screen, but black screen out:

I'm not sure to understand. Is there anything I can do to get the Colecovision video through OSSC?

Hi all, I just found this topic while searching a way to modify my Colecovision. I got the console when it came out it france in 1983. So it is a PAL RGB / SCART version It was still working on my 2013 Samsung 55" smart TV, as there were a SCART connector on it, but I just replaced my TV for a Philips 65", and no more SCART on it. I bought an OSSC 1.6, which works perfectly with RGB SNES (after I modified the AV cable to use Luma sync ) But when I connect the Coleco, I can get sound, the OSSC shows a sync but I can't get an image. It seems the Coleco only has C-sync which is not compatible with OSSC. Has someone already faced that case?