HP Forums

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?

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

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.

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