Learning Retro Computer Electronics Fault Finding and Restoration

Summary

Have you watched retro computer repair YouTubers and thought you would like to try that? Well, you can!I am going to show you the retro computer repair and refurbishment process I have put together through hard experience so you produce less magic smoke, miss fewer opportunities, and collectively more machines are salvaged from the computing graveyard.Before we begin, though, I am NOT an expert and this is not an expert guide. I am learning and documenting over time, so you can avoid my mistakes.You will still make mistakes, though, and that is ok! While the vintage computer refurbishment hobby (and it is a hobby in its own right) is not the cheapest, it is not the most expensive either, so consider any mishaps along the way as learning experiences.The goal is simple:Make your machines safe to power upMake them work reliably so you can have fun with themKeep them usable long termYou will notice I do not “retrobright” them with chemicals to remove yellowing, I do not focus on aesthetics much at all. This is not about achieving museum-grade restoration but to have something working (and hygienic) that you can enjoy owning.A guiding principleAlways move from:Least invasiveLowest riskEasiest to undobefore more complex and destructive steps.Many faults can be found without desoldering anything.Retro Computer Electronics Troubleshooting ProcessA warning before we start – If it ain’t broken don’t fix it. It is easy with fragile, vintage electronics to damage things that were actually working fine!Common casualties:Keyboard membranes and ribbonsBrittle plastics and key stemsOld connectors and crimpsIf something works and is not causing problems, think carefully before dismantling it.Diagnostic Roms and Test Harnesses Diagrom on an emulated ROM chipSome systems have diagnostic tools and test harnesses that help with diagnosing issues, for example the Diagrom for the Amstrad CPC.The minimal version will usually be a replacement ROM binary/firmware download intended to swap wi...