I own 2 calculators HP 48G, one 32 k RAM, the other one 128 k RAM (+ version).
The 48G works but apparently does not execute the instructions correctly. The 48G+ is affected by a strange stain on the display, even when it is off.
Are these products still assisted for repair ? Could I be addressed to a repair service ?
I have an HP48G+ with a faulty on off key, to on and then to turn off, the calculator works fine once It’s on
it’s just that one thing