HP35 problem with a calculator, maybe due to a faulty charger

[aurelio]

(03-21-2021 08:20 AM)teenix Wrote:  It does look clean

If you have another 35, maybe you can confirm the CPU board works or doesn't by swapping for a known good one.

Unfortunately, there is a small risk that swapping may damage a good CPU board. If you have a multimeter you can check the power supply rails first to see that they are all good.

The test points are labelled here from Tony Duell...

https://www.hpmuseum.org/cgi-sys/cgiwrap...i?read=385

cheers

Tony

Thank you Tony, CPU boards swapping was the first thing that came to my mind, but I also thought about the risk, however minimal, of being then with two 35 opened and, even worse, both not working...
Thanks for the advice, I measured the voltage and read, with my 8.5 V multimeter, where it should be from scheme 8.2, but I do not know the accuracy of my instrument and the tolerance allowed.
I measured on test points what I could measure with the multimeter i.e. Vss = 6.49 (expected value 6 V) and Vgg = -12.94 (expected value -12 V), what do you think of these results?