Hp91 with very dim display

[James Linder]

Thanks for your help! I’m going to take voltage readings with my multimeter working from the battery to the power supply and beyond to see where the voltage first drops and replace or re-solder the component where the problem begins. I expect it will be within the power supply but will also focus on the press/pull connectors between boards since they are obvious potential problem sources. Since it appears this 91 had never been opened up before I got it last week, it’s not likely a connector unless it was dropped and this doesn’t appear to be the case.