Sorry to post this, I'm sure you guys absolutely hate seeing these things, but I've been working on this Jaguar for several weeks now and am at the point where I could use some assistance. I got all the information I used to fix this Jaguar (including troubleshooting tips and double checking methods) from the AtariAge forums and think you guys are my best shot at solving this. Maybe this could even help people in the future fix Jaguars that weren't as simple as replacing 3-4 things.
So I got a broken Atari Jaguar off a guy I've know like three years, and I know he had been sitting on it for at least that long. He has a bad habit of buying broken consoles with intention of repairing them, but he doesn't even have the tools to do it. Anyway he finally agreed to sell it to me, and it was a super good deal and is one of the only consoles I'm still missing, so I wanted to start working on it right away. I have quite a bit of experience doing some basic console repairs and modding, hell I even recapped both the monitors in my arcade cabinets. Figured I had a good shot.
Plugged in a cart, turned it on, nothing. No power. Got pretty excited, no power is usually a pretty simple fix for most game consoles. Spent some good time doing my homework (mostly on these forums), and sure enough, UC38, REG1, and C134 were all blown to high hell. Someone used the wrong power supply on it (which I find interesting since he included a 1st party power supply and video cable with it... maybe he bought those himself who knows).
Anyway, bought a new U38 and REG1 off console5 and caps for C134 and C158 (just in case) off mouser since I needed caps for more Game Gear repairs anyway. Got em soldered in, turned it on, eureka, we have power boys. But the video... is just this - https://i.imgur.com/GnuJM1l.jpg When you boot up a game, it's dark blue on black, then about 5 seconds later (after the Jag splash screen finishes I'm assuming) it changes it to like blue and tan, which I'm assuming is the game video. No sound at all.
It gives the exact same video using RF or the composite cable (for RF I'm using a TG16 cable since they are compatible). I have an official Jag composite cable for it as well as a third party one, both give the same thing so nothing is wrong with any of my cables. I have 3 games for it too, so I doubt it's any of the carts. Also does the same thing if I use a Genesis model 1 power supply (which is compatible with the Jaguar). I have to say, I'm pretty stumped, and am looking for things to test next, and where to go from here.
I did a bunch of power readings with my multimeter, and the U38 itself seems to be functioning properly, all the power readings are what they should be. C158 is also giving me the amount it should (it isn't too low). I was hoping someone could help me rule out my REG1 being the culprit. Using Pin 4 of the U38 as GND, I took power readings of all the pins. Pin 1 gives me 5V (which is correct I believe), Pin 8 gives me 11.47V (which I think might be high but I have no idea), and all the other pins give me a reading of 0V. Is this correct?
Also I remember somewhere on the AtariAge forums someone mentioned you can test REG1 by jumping Pin1 of REG1 to L7 and get audio if your REG1 is broken, and that trick did not work for me, I still don't have audio, which makes me think it's something else. The only thing I have not done to this Jaguar yet is a full recap, but I'd like to avoid that if it won't do anything. None of the caps are giving me readings that are suspect (IE, incredibly low), nor do any of them appear damaged (C134 was unbelievable obvious). I have a full chart of the capacitor readings from my Jaguar if anyone is interested in seeing it.
Sorry about the huge wall of text, I want to get in as much info as possible initially so no one is like HaVe YoU tAkEn VoLtAgE rEaDiNgS yEt?? (lol)