G07 shutdown, X701 brings back to life

DogP

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Hey,

I was playing Galaga the other day, and the monitor went blank. I looked closer at it, and I hear HV initially, but then it shuts down. The B+ is too high. I assumed it was C511, and the caps looked old, so I did a cap kit, but that didn't fix it.

So, I followed the flow chart, pulled X701, and it comes back to life, so it says to check all 900 components. I've never personally come across this problem, but I went ahead and resoldered all 900 components (some had bad looking solder joints), checked the active 900 components, but didn't find anything bad, and it still doesn't work.

I checked some of the resistors, and I'll go back and check the rest... but does anyone have any suggestions on what to check (common problems, etc)? The voltage regulator isn't a 900 component, but would that cause this problem? I'm just looking for ideas so I can hopefully fix it tomorrow night.

Thanks,
DogP
 
Cool... thanks guys. I'll swap out the regulator transistor tomorrow (that's what I suspected first, though I was thrown off by the flow chart suggesting to check the 900s, but not the regulator)... then I'll dig deeper if I have to. Oddly, while I've fixed quite a few G07s, I've never come across a dead regulator (most have been exploded flybacks and caps).

DogP
 
Did you replace R908 when you did the cap kit?

No... I had a Zanen kit laying around (caps only), so I installed that... but I just checked R908 and it was open. I replaced it, and it's working great again. Thanks!

DogP
 
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