HP-67 failed main board?

[naznerd]

Hello all,

I have a nice HP-67 that was working fine including the card reader. I set it down for a couple of hours and when I tried to use it again, it displays "-00000000000 00" as soon as it is powered on. This unit is in great physical shape, and has zero corrosion in it. I checked the main logic board for bad solder joints and found none. I've tried using with and without the original HP charger, and it makes no difference. I used a multi-meter and probed voltages on various chips. Most the of the chips shows ~6v, however the large AMI chip has ~17v, which seems wrong? I'd appreciate any insight into what the issue might be and how to correct it.

Thanks!

Larry