Hey all,
I'm a newbie to working on pins. I found the awesome pinrepair site and read it top to bottom. My only idea left is to get a new cpu, so wanted some guidance first.

Some quick background. Dad bought dragon as an xmas present back in the 90s. It worked great! No free play mod. He said it was a way for us to save for college (we knew where the key was hidden). Years later I have a game room want to have pinball. It didn't start up... Bad power supply. So, bought a new one. It is now working great, but has two issues.

1. Won't save high score and credits don't decrease. High score showed 444444 on all displays. Voltage to memory chip was good, so I bought a new chip from docent. Put that in tonight, reset memory, still doesn't store. Shows 155555 now.

2. It takes 4-5 off and on cycles to get displays to work. First its black, then ghosting, then works until turned off. I have new cables on order from docent.

Any help or advice would be greatly appreciated!

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Thanks guys. The nicad was a replacement that was still reading around 4v on pin 22 of the memory chip. I don't think you are seeing corrosion, it's old tape. I pulled out the battery and installed the recommended AAs. Reset the audit memory several times with no luck. Good news is that it turned on fully on the first try. Here's the weird thing. The voltage at Pin 22 now reads 1.471v. What could cause that? I checked the battery pack multiple times and it was reading just below 4v.

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Thanks noflip95! The diode is bad. I assume it is a 1n4004 - 400V/1A Diode?