A while ago I bought from eBay an HP-41CX main board (as-is state) to upgrade my 41CV one on my fullnut calculator. This is the board version I bought:
However after replacing it I observed that it does not power on at all. I have a basic knowledge in electronics, so the first thing I did was to desolder and inspect the electrolytic caps in case they had dried out (elevated ESR). But they were perfectly fine. From this point onwards, I don't know how to continue the troubleshooting process. Particularly complicated is the process of measuring voltages due to the way the calculator is assembled (it needs to be closed so batteries make contact with the main board).
Any idea of other potential culprits?