Having some issues with a Turtle in Time PCB that was working many years ago, but due to various reasons I hadn't had an opportunity to play again until recently... I'm having some issues with sound, screen colors, and random resets (?). I don't see any obvious signs of corrosion or damage, beyond some minor corrosion on the K053260 chip which I cleaned up using deoxit, a brush and some IPA. Hoping someone here can help!
The sound either doesn't work at all, or only intermittently works if I press down real hard on the "L" pot. I've tried cranking the pots in every direction with my cab volume at full blast, and the sound is set to mono in the Test menu. Deoxit on the pots didn't seem to help. I may try to reflow the K053260 unless anyone thinks that isn't the problem.
The colors on-screen will occasionally turn to a very yellowish-green tint; sometimes, it's totally random, sometimes it happens if I press down on certain areas of the board, notably the JAMMA edge. If I press down hard enough, the entire board will crash and reset. I noticed most of the socketed chips seemed to be loose, so I gave them a nice push. Didn't seem to help.
Note that I ended up trying to reflow the K053260, which is why it might look a little haggard on the "bottom" and the "right" side (as pictured). All of the pins are solid, and I checked with max zoom on my camera for bridged pins/pads (didn't see any). I didn't touch the other two sides of the chip, since I didn't notice any sketchy looking pins/corroded solder. It seems like the weird color shifting and random resets went away, but still no audio. I got sound briefly the second time I booted it up, then it went away.
Something wrong with the blue signal. Trace it to wherever it goes to and do continuity checks along the way. It's pin 13 parts side on the jamma connector.
Some updates in a nutshell, I'm too discouraged to type anything lengthy:
I purchased all the caps thanks to nassekova's cap map; recapping the board did not seem to resolve the problem.
I am not an octopus and I don't have fancy clips for my meter, so I wasn't able to get around to testing the pots. I know I should've probably done this first, but a recap wouldn't hurt anyway. Especially after I noticed one of the caps on the board was the wrong value!
I'm no longer seeing the color and reset problems.
After the recap didn't work, I tried reflowing the other two sides of the chip.... aaaand I screwed up. A bunch of the legs on one side of the custom sound IC are bent and bridged. Not sure what happened. I think I used a hair too much solder, and I probably ended up bridging them when I was using wick to try and remove the excess solder. I decided to stop while I was ahead and find someone with a steadier hand, hot air experience, and magnification to do this before I end up destroying the board. I suspect the custom is dead anyway.
Already approached a few people about potentially fixing it, but if you're up for it (and you're in the US), shoot me a PM. I'll update when it gets fixed!
Final update here with a very pleasant end result.
I sent it off to someone to get it looked at based on a recommendation from our very own @/ShootTheCore; it's now working perfectly. There were a few issues:
Palette RAM went bad; replaced.
Tilemap chips needed a reflow, but worked fine. Intermittent graphical issues are now resolved.
Konami sound IC was removed, pins were realigned as much as possible without risking further damage, and IC was reattached; one pad was lifted in the process, and a bodge wire was routed between the connected pin and the Yamaha chip. Sound issues are now resolved.
Moral of the story:
Just reflow stuff on old boards if you have the time lol.
Be careful reflowing surface mount chips if you're a bozo/if you lack experience. Don't try and be cool and do drag soldering unless you're good at it.
If you don't have the time or you think you lack the skills required, just pay someone else to do it instead!
I'm pleased with the end result overall. I was reasonably confident going in, but I think I screwed up not taking my time when I tried reflowing the sound IC, but I probably wouldn't have caught the palette RAM problem since it didn't fully manifest unless you left the game running for over an hour, and I don't have chip testers, so it may have been better if I had just mailed it off to someone to start with. A chip tester is now on the list! Maybe this thing, but it might be overkill.
