HP-67 failed main board?

[naznerd]

(10-15-2024 10:16 PM)teenix Wrote:  

(10-15-2024 02:24 AM)naznerd Wrote:  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"

This is usually caused by a ROM failure, where the HP program is stuck in a continuous loop at start up. As the display registers (A and B) are reset to zero at this point, the display shows all zeros. The fact that this is happening shows that the calculator otherwise is functional.

The attachment shows the same from my emulator

cheers

Tony

Thanks Tony.