Tag Archives: testing

SmartParallel: mystery solved

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Although the stripboard version of the SmartParallel board is working, one niggle remained. When the printer was switched on, but the SmartParallel board wasn’t powered, I was getting random resets of the printer. They weren’t as frequent as with the breadboard prototype, but they were there, sometimes. Also, there was a problem with signals effectively ‘back powering’ (I’m not sure… Read more »

First PCB and more mistakes

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Okay, so I’ve already fessed up to some errors I made with my first-ever PCB. Now I’ve discovered another, and it’s a doozy. It’s also a valuable lesson. I’m waiting for a few bits of kit in order to do surface mount soldering. I’ll be writing more about this when it’s all installed (but as a teaser, it’s a hot… Read more »

Epson MX-80 Part 4 – ESR check of the dodgy caps

It seems strange that both the capacitors and the transformer – the chief suspects in the investigation as to why my Epson MX-80 F/T III dot matrix printer belched out smoke – tested fine with a multimeter. As far as the capacitors were concerned, I measured resistance directly across their leads (having removed them from the circuit board) looking for… Read more »