TomelloSoulMan

It was a fun one! Thanks for opening the competition @Al_Nafuur!

Ok, here's the actual diagram ?

Sorry for necro-posting... Last weekend I was in a retro expo building one of this mods for a clone and a nice guy came to my side to see what I was doing. I explained it and talked him about the problem I had with this mod while splitting the output and he suggested what I think is a pretty good solution, only adding another 3906 and two resistors (18 and 75 ohm), to get a secondary video output. I built it into my clone and it works great! Image quality is not affected either I connect the video capture card or not, it's always great in my CRT. I made a diagram showing it, what do you think about this solution? My only slight concern was if it could overload the 7805 but I played for a long while and it didn't burn itself... It gets very hot, but it did that before, as it isn't mounted into any heat sink.

Indeed, looks like a TIA issue

Great! Wow, that was fast

Great idea! It's always nice to have a place where to track progress in a game. I also think that the single score per user should be the default, because you can take a look at the leaderboards from the PlusCart itself but it can't display all the entries (or I don't know how to do that), so only high scores can be useful in that case Great! No rush at all, I only wanted to expose this idea and I guess you already have a lot of work with the PlusCart itself

Great to see more games added to HSC! I had a little suggestion but don't know if this is the best place to do it. I was thinking if it would be better to keep only one score per user in the leaderboards, the highest one of course, as it's done in other online leaderboards like the RetroAchievements ones. I feel the leaderboars i'm in get a little polluted with all my scores, and this might get worse as more users get into this. This should give visibility to a greater number of players and not only the best or most constant ones. What do you think about this? Just putting my 2 cents

It seems you have the same problem as in this thread: If the adjustable inductor is not broken by now, you could try to adjust it again to its previous settings, but might be hard. Did you consider doing an A/V mod on this console?

No problem Simon, in the meantime I managed to repair my original Jr and it's working as neatly as before. I can split the signal and it shows nicely both in my CRT and capture card simultaneously. Maybe I'll replicate the same output circuit the Jr has (with the CD4050 and same D/A resistor values) on one or both of my clones, but it's no more a priority. I have to admit this conversation you're having flies straight over my head. I need to learn a lot on this subject, stop being just a blind circuit replicator and be able to understand and analyze what I'm doing. Maybe the wiki.analog.com link provided above will be a good starting point for me.

Thanks for the tip and the link, I'm going to look into this as it seems a pretty neat solution.

I fixed it! Dang, it was a short in the end! I swear I've tested each single pin with each other before, but didn't detect this. I've done it yet again and BOOM, there was a short between A2 and D2 near the CPU socket. It seems like I scraped the tracks cover while unsoldering, and some solder leftovers did the rest. I can't stress enough how thankful I am for all your help, Alex, and how shameful I am too for such a silly issue. Now I have another problem: reset and game select switches are not working, but it's an easy fix because the jumper is working ok (so, no RIOT related) and the end of the tracks of the plastic band that's inserted into that jumper seem to be very scratched (too much wiggling in this process, I guess). I'll figure out how to make a replacement, with some push buttons or something, but the most important issue is fixed! Yay! Good to know, I'll add that to the heap of things I've learned in this process

This might be out of my understanding, I guessed the horizontal sync was working because of the PALI/PALS signals are present in the PAL TIA, connected to the schematic part where the 4.43MHz xtal resides. I didn't know well if the 3.54 MHz signal was used by the TIA in some way or only carried by it to the CPU and RIOT through O0 and O2, as you say. I have a lot of things to learn yet... I'll do some more tests this evening with the bare cart to make sure it's receiving the 5V signal and everything is ok. It all points to what you previously said, the console behaves as if there was no cart connected at all, but all connections seem ok. I'll post results later, but I'm slowly losing faith in that I can repair this console, which is sad because it's my only original one. At least I can take out the video signal A/D converter circuitry and use it in one of my clones, to make it a proper gaming/streaming platform...

And now comes when I don't forget the image and actually attach it ?

Ok, I've done that again. This time I've tested with a bare cart connected to the port to make sure all the pins are making contact. Everything seems to be connected where it's intended to be, with no shorts. At this time the only part I'm suspecting of is the clock circuit (see attached image). I'm not able to check the signal values properly with a 0.5s polling time multimeter, but it's a suggested culprit of this kind of failure in the service manual, and as I have some spare 3906 transistors, I guess it's worth the hassle to replace them and test. What I don't have is a 3.54MHz xtal (as stated in the diagram), would a 3.579545 one do the trick? Thanks a lot for the PAL service manual, will take a dive into it right now.

Ok, thanks for the tip! I was suspecting this could be the culprit... However, I've done the tests and RES line is at a steady 5.02V (4.96V on CD4050 pin 5 iirc). VCC seems ok too. I don't know if there are more tests I can do with a simple multimeter, and I'm afraid I'll need an oscilloscope to check all reference values as stated in the Atari 2600 service manual, which is not easy to follow for me as it's not oriented for Jr models, and component names are different. Does anybody know if there's some service manual adapted for Jr models?