Sega Saturn repair... weird issues.

yes i had a problem like that once it was electrolytic capacitors on the power board
replace all of them on the power board.

 

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ok but if you get a chance replace all the caps on the old power board as theres lots of different boards versions.

 

PSU with a bad part certainly could produce these odd errors - particularly if after having it running it plays worse/better during the first 10-20 minutes of gameplay or better/worse after 20 minutes of gameplay. Warming things up could cause the individual components to perform better/worse or cause solder joint expansion which can do all sorts of weird things.

Bad caps sounds like a potential culprit too, replace the obviously bulging/popped caps with equivalents. AFAIK the uF number should be identical 100% of the time but the voltage should be equivalent or higher, never lower. If you need help with this or want someone to do it I'm your man (assuming you're within the US or Canada).

Clean the laser as a means of routine maintenance with a q-tip and rubbing alcohol, dust it all since a small amount of overheating can cause intermittent and strange problems with a lot of components in that thing, get that 20v difference on the A/C adapted too either by putting in a PSU from an American Saturn (it'll drop right in without needing to do anything and it'll plug straight into the wall) or by getting a voltage adapter.

 

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