SNES CIC failure?

SNES APU reset failure

Hey guys. I have a problem with a 1chip-02, and I wonder if it is related to the CIC. Short version - despite cleaning the connector (and even using another one from a working system), a game will sometimes not boot. Power off and on, and it might. Reset button will cycle the SNES, but the game rarely will boot if at all after reset. Reset typically = black screen.

I thought perhaps there is an issue with the CIC or its circuit. I know a lot of you guys have done work with a SuperCIC - that is something I might consider, but I am trying to get info on stock symptoms first.

Thanks.

EDIT: Changed topic title to reflect actual problem.

 

remove the reset switch and lift pin 4 of the cic

 

Well, that would certainly disable the CIC chip and eliminate the reset switch as a possibility. Have you encountered issues like this before? I would like to try to monitor the situation via meter/scope if possible. They may have nothing to do with what is going on, although the almost 100% failure to reset is rather interesting.

 

Well, I ended up lifting pin 4 on the CIC. No change.

Replaced reset switch. No change.

Not sure what to try next. Sometimes cart boots, sometimes it doesn't. Reset switch seems to restart SNES into a freeze. Best thing to do is power off/power on to try again.

It will sometimes work on the first try, and will usually work on the second try if a second try is needed. You could almost just shrug and ignore the problem, but I would like it to fire up and have it work every time.

 

So the long story short on this - the board didn't have a good connection from APU pin 16 and the associated via. Pressing reset would reset all appropriate components except for the sound module. This resulted in the freeze after reset. This would also cause the cart boot sequence to be a bit of a dice roll each time. Improving the connection from pin 16 to the via restored the reset switch functionality and also helped the carts boot properly every single time.

Just adding this info for anyone else that may encounter this niche problem.

 

Good job on getting it fixed! Another SNES rescued.

 

Thanks! I've seen a lot of people use the phrase, "Your SNES is on the way out" on various boards whenever someone has a problem, is told to clean their system, they clean it, and it still doesn't work. Hopefully that has stopped in recent years and more people are either repairing their systems, getting someone else to fix it, or selling broken consoles to people that can repair them and keep them going.