Another Hamfest find is the Sinclair Radionics PDM 35 digital multimeter. Having grown up with ZX Sinclair Spectrum clone, and reading a lot about Sir Clive Sinclair and his creation I wasn’t about to walk by this. If the look of it is a bit calculator-like, that’s because they actually reused a calculator enclosure! This was a cheap model, selling for 33 pounds in the 70-s and 80s
This is an old repair I did a while ago and posted on thinkpads forums. Reposting here to put it all under one roof. We have quite a few IBM Thinkpads X31 in the family. They are built like a tank and work well enough to keep using them despite 2003-2004 datecodes. One day two of them started exhibiting identical symptoms- they would just refuse to turn on. No lights, fans or other signs of life. Luckily I stumbled on a schematic on the web, so that was a good starting point.