HP-22 1706A12167 in search of advice

[albertofenini]

Hi everyone,

I'm not into the Woodstock's since I find them more fragile than the Classics
but I was looking for something usable every day and I bought this HP-22

I usually buy those where the seller had no access to the original power supply just to avoid fried ones, so this one looked good to me

I was a little disappointed when it didn't turned on with a good battery pack but it
turned out that the - contact on the main pcb was fractured, probably by forcing a battery pack in place, who knows ... and thus missing some electrical continuity on those traces

I have fixed it by soldering on both faces a small wire, but I'm looking for an advice on how to reinforce it, physically speaking, just to avoid more damage with the daily use, any idea ?

Also, the display is missing a digit, I have tried swapping it with another, which worked fine, so I'm afraid this is not an easy fix

A while ago someone mentioned that any financial calculator with the delta% function (the triangle key) can compute cost, price and margin without the need to enter a program, which is why I have purchased this little thing, does anyone recall where that post is ?

Thank you so much and take care !!

Pictures can be seen here : HP-22 1706A12167