HP-42S battery drain

[Marcovecchio]

Thanks for the schematic link!

Unfortunately, I triple checked the components, I removed them all. There are not many, in fact.

The board has no mods too, the crystal is the original 32kHz. But there's something on Lyuka's pages that caught my attention: there's a mod regarding display contrast, he mentions a switching transistor that may fail inside the processor. The display on this calculator is not very good: when I increase contrast, it seems the background gets proportionately darker. It's a long shot, but this might be the problem. Later I'll print and study the schematics, and if I have the patience, I'll try to pinpoint the processor pin which is drawing the excessive current, to see if it has something to do with contrast.

Thanks for the help!

Eduardo