HP-41C Tall Keys Strange ON Behavior

[aj04062]

Any theory as to why a HP-41C would turn on with almost any key but not with the ON button? I can turn it off (I think the display just goes blank as it will record keystrokes), but ON will not turn it on.

I just swapped the LCD from a 2-3 year newer CV.

The only way I can get MEMORY LOST is to short out the battery terminals.

[Luiz C. Vieira (Brazil)]

This time I must tell I never heard of it...

If I have a calculator with this behavior I'd check the LCD soldering points and the connection between the MBoard and the keyboard (the zebra connectors).

Success!

Luiz (Brazil)

[Raymond Del Tondo]

As Luiz wrote, please check the contacts.

Another idea: The LCD driver of the newer CV may not be fully compatible to the old main board, see notes on the Systemyde 41CL when using in an old 41C with square LCD controller cases.

HTH

Ray

[aj04062]

I don't think it's the display driver as the SN is late enough. I've cleaned the zebra and board contacts once. I guess I'll look at them again.

I'll try the board in another unit to see if that changes anything.