Hi,

I have a wpc95, which keeps settings, but not the time and date.
Diode D2 checks out ok, u8 ram shows 4.3V on pins 26-28.

Any pointers what I should check out next?

If I set the time and date, it stays correct as long as the machine is on.
When it's powered off, it stays ok if I check within approx 30 mins...if later , its gone again.

So it's not keeping it at all, for a longer period on battery power.

Which pins could I check on the asic for correct battery voltage?

My guess is that I have voltage loss to the asic...

I inspected the board closely yesterday, and saw some small remnants of the blue stuff (alkaline) on the legs of the mpu. Rinsed the board with vinegar and alcohol. There doesn't seem to be any trace damage.
Board is now drying.

Measured the voltage to ASIC and its 4.3v and to the u21 also, so battery power is getting there.

At the moment I don't have a logic probe to test. Going to pull the ASIC and reseat it just to be sure.

Thanks for all the pointers guys, I really appreciate it. Will follow up if I have more progress.

I put the cpu board back yesterday. Pulled the security chip, asic and mpu and rinsed the board, and the problem seems resolved.