Resets are low 5v going to the CPU. Check the 5v test point and and any connections from the power supply board to be cpu.

Check the 5 volts and 12 volts at the top of the board. If only 5 volts is being affected replace C2 (100mfd 35v) and C7 (330mfd 25v). These are radial (vertical mounted) electrolytic capacitors. You should be able to buy them from Fry's Electronics and possibly Radio Shack.

Any burnt pins or discoloration on the white part of the connectors on CN1 or CN2 ?

Definitely you would want to change C2 and C7 regardless as these frequently leak and cause resets as well, even damages traces under the capacitors.

So 12 volts being low, it can be between the bridge rectifier (which is better to cut 3 of the legs off the board close to the part are you can) and F1 and F2 (10.7VAC input into the bridge rectifier) fuse holders.

Do all the fuse holders on the power supply have good tension on them? Push on the fuse a bit to see if the fuse holder spreads apart. If they are all good then the bridge rectifier sounds like the issue.

Ok. For now, I would go purchase a new C2, C7 and bridge rectifier. Change only C2 and C7 first and any other capacitors that puffed out at the top, which is a sign they failed. Then need to test out the bridge rectifier before trying to cut it out. It is very easy to damage the board. I was hoping Pinwiki showed how to measure it. I'll have to look elsewhere for that it seems.

I doubt it, but it is possible just C2 and C7 may take care of things for you. I would try that first really.

http://www.pinwiki.com/wiki/index.php?title=Data_East/Sega#Power_Supply_Issues

Could you post a picture of the power supply? Front and back would be nice.

Purchase C2, C7 and the bridge rectifier and start with replacing C2 and C7 and see what happens first.

bumping this thread..MY JP is resting..5v drops to 3.5 then back up...Should I replace C2 and C7? who sells these..thx

Electronics stores near you should have them.

Otherwise, www.mouser.com to get them the fastest from the internet.