HP-46 not working

[Ignacio Sánchez]

Hi again,

another question about an HP-46 I have recently obtained.

It is a 001 version, with the led display installed.
When I switch it on it doesn't work, but when I am pushing back the "line" button to off, the whole led screen just blinks for a milisecond showing a zero in the very right side. It also happens in the turning on process, but more clearly when I turn it off. The printer does not respond.
Any kind of help/opinion about what to do is welcome. I would like to repair this amazing machine (very dirty in this moment)

Thank you very much in advance.
BEst regards to everybody.
Ignacio

[Donald Williams]

I have not observed these symptoms on a calculator, but I have often seen it on other electronic devices. What I generally discover is a power supply that begins oscillating under load. It is often difficult to trouble shoot, because when you isolate the supply (remove the load) it will behave normally. Then as soon as you put the normal load back on, it breaks into oscillation. That might be the problem. Good luck with your repair.