HP48G Hardware Troubleshooting Questions/Tips

[Marco Polo]

(10-11-2019 04:07 PM)Phenixg Wrote:  Here are what I can see:
* There is no sign of life on the display. Nothing when I just connect the batteries, nothing when the "ON" button is pressed and after.
* The "ON" key seems to work: I measured voltage between ground and the ''ON" connector, I get 4.x volts when the on button is pressed; I get 0.0 volt when released. I also measured the resistance, when the on is pressed; the value seems to vary.

Have you tried to adjust the contrast?
It happened to me a "dead" HP48, but for some reasons the contrast defaulted to minimum.
Pressing some times ON+ solved
:-)