Opening a 31E

[jwr]

I'm trying to restore a 31E and I've hit a snag at the very beginning: I can't open the case. I've removed the two screws above the battery compartment and tried to pry the case halves apart, but they are firmly hooked together at the bottom. I don't want to use more force, because I can already see a crack appearing in the case.

Does anybody have a picture of an opened case, so that I could see the hook mechanism? Any suggestions on how to pry the hooks open?

[rprosperi]

An infamous problem, likely the most common complaint about opening an HP Calc. for service (possibly tied with removing labels from Classic models w/o damage).

There are several 'proven' methods, but none are perfect, nor stress-free, but here is one that seems to work for most people:

https://www.hpmuseum.org/cgi-sys/cgiwrap...i?read=925

[jwr]

Thank you! That link was golden. I was able to open the calculator. Wow, this thing really wasn't meant to be serviced much.

Unfortunately, it seems that this particular 31E is toast. I was hoping that cleaning the contacts (PCB, chips and display pins) would help, but the display still only shows changing selections of some 8s and 9s.

[Dave Frederickson]

SLP to the rescue.
http://panamatik.de/html/hp_low_power.html