Hi, I've just finished recapping a Sega Game Gear. Now when the device is switched on with the brightness turned up, it will switch itself back off again. After a couple of attempts, it works fine, until left off for a period of time. It sounds to me like a cap issue, but it has just been recapped, so I have no idea where to look. I don't have spares for every cap so I can't just go through and replace them all again, so I'm hoping someone will have some idea where/which caps to look at. Also, I noticed one of the pads on C1 is completely destroyed. Is it safe to use the console without this cap? (Btw, I removed this cap from a fully working console which still worked perfectly, so this shouldn't be causing the issue above). Any help/advice would be appreciated.
It might be a bad connection. One of the caps may be soldered on bad. It might also have something to do with the power board unless you re-capped that as well in which case it would probably be the former. I had a similar problem with a game gear I fixed once. Try putting some electrical tape over the caps or running it when it isn't closed and see if it still powers off. I had positioned it in a way where the caps were shorting out. If this works, just figure out where it is shorting out and reposition the cap.
Thanks for the response. I should have mentioned in the first post that I have tested the console with 2 fully working power boards with the same result. When I did this, I left the console open so I don't think shorts are an issue either. I have replaced a few of the caps for a second time, as well as lifting a few caps from a working console to see if I could replicate the issue. None of this has helped :/ I don't have a capacitor tester, but I have read that resistance can help to diagnose dodgy caps. I have taken a few readings from this and a working game gear, and while most readings matched between consoles, a couple were lower in the faulty console. Should I read anything in to this?
Maybe it's something as simple as bad batteries/PSU, try switching those too if you haven't done so yet.
If it worked fine before you recapped it (other than the sound / dim screen / whatever issues you had), then you should probably blame something you've done. Shorts could well come from the soldering process, so don't rule it out.
Tried different batteries and a PSU as well, and it does the same thing. Also, the console does work fine after it has been turned on a few times, and works first time if turned on at low brightness, which is why I'm thinking it isn't a short. Though I will check the board again to be sure. The console wasn't working at all when I got it, a few of the caps were a bit wet inside the plastic cover, but the board was completely dry and doesn't seem to be damaged at all. I did clean the board and all of the solder pads before replacing the caps. I'm going to take a few caps out of a working console to put into this one to see if that solves the problem, at least then I will know which caps I need more of.
Just got the console back out to do some more troubleshooting, and it seems the issue has resolved itself. No idea what was going on before, but it now works 100% of the time, even at full brightness. Would still be interested if anyone knows what C1 is used for.
There's at least three different models of GG console with completely different internals. What is C1 in one could be something completely different on other board model. So maybe give us a pic of the capacitor you mean ?
At some point my GG (same type as yours) had a broken trace around that region. It turns out there's a voltage comparator circuit on the power regulator board which measures the battery level. It need some sort of feedback from the board and the circuitry which generates it is exactly around that capacitor. So it would light up then shutdown almost instantly as if it had bad batteries. Trace mended and it's been working fine since then (3 years ago).
