HP 32SII success and woes

[Sanjeev Visvanatha]

OK, I performed some surgery today and some transplanting.

I removed the PCB using flat nose mini pliers to untwist the clips holding it down. I cleaned the zebra strips and contacts with isopropyl alcohol. After careful reassembly, I was still presented with the same issue of gibberish on the screen.

Then, I removed the PCB and LCD from the 10B, and transplanted the PCB and LCD from the 32SII into the 10B front body. After carefully reassembling, I ran the self test, and was still presented with the same gibberish. This precludes the layered keyboard assembly of the 32SII being the culprit.

I now conclude that that something on the PCB is to blame. I used a magnifying glass to carefully examine all traces, the pins for the IC and did not see anything wrong.

I have managed (on occasion) to get the calculator working normally, for short periods after removing the batteries and draining the capacitor. But after a short time, the calculator reverts back to the weird display of characters. I noticed that there is a 10uF capacitor on the PCB next to the positive battery terminal. My last hunch is that the capacitor is faulty. I know blown capacitors in electronics can cause all sorts of strange issues. This is only a hunch, and probably the last thing I can think of that I could try on my own.

Thanks for all the help. I opened up 2 Pioneers last night for the first time, and now know how to remove the PCB and clean the contacts, etc. So the learning experience has been invaluable. I just wish I could have gotten the 32SII working in the process.