Pot-o-gold version 580 has an eprom checksum error

[cjbelev]

I recently had a pot-o-gold machine that had been out of service for a year. the monitor wasn't working. I was able to repair the monitor, but when I turned it on I am now getting an eprom checksum error. I don't know if this is a battery backup issue or memory reset. I don't want to default the machine. any suggestions would be helpful. I was able to get the machine to work and clear the fault, however if I shut off the power the fault will come back. Does the Supercapacitor on the board commonly degrade and need replacement to solve this issue?

[asgard]

You need to change the U3 chip. It is a clock chip.

[cjbelev]

Where might one find a replacement chip?

[cjbelev]

I changed the U3 clock chip, I was able to set the present time. I placed it in diagnostics mode, DIP 8. it booted up and works, but will still get a checksum error if I shut it off. any other options. How is memory maintained during a power loss?