Tag Archives: repair

Repairing a BBC Master #2: Basic steps

First, do no harm. Second, check the voltages. That’s how the Hippocratic Oath starts when adapted for electronics. If the device under test is not getting the proper power supply, then you can’t reasonably expect it to work. But there’s something I wanted to check, even before I apply power, and this turned out to be a learning opportunity. With… Read more »

Repairing a BBC Master: #1 – plan of attack

So my poor Acorn BBC Master Turbo is sick … again. And I feel a little bit responsible. Quick recap: the Master developed a problem some years ago. This was ‘fixed’ when a very generous person donated a motherboard from his machine. I never did find the cause of the problem. Since then, however, the machine has spent a lot… Read more »

Casio fx-590 – reviving an old friend

It was about to go in the recycling pile when I thought, “I wonder if I can save it.” There’s no telling how old this lovely Casio fx-590 calculator is, because in spite of deploying my best Google-fu I can find very little information on it. One source suggested that maybe it came out at the beginning of the 1990s…. Read more »

Fixing an e-bike pedal sensor – part 2

Well, it looks as though this series of posts (of which this is the second and possibly last) could be badly mis-titled. For a start, it doesn’t look as though the pedal sensor of my malfunctioning e-bike is faulty. And it now appears unlikely that I’m going to fix anything – not in the near future, anyway. However, I had… Read more »

BBC Master power supply – repair or replace?

There are three things that are certain in life – death, taxes and blown capacitors in old electronic equipment. But at least you can do something about the last one. Powering up a 35 year-old computer that has sat in a loft for the past two decades is foolish. But we did it anyway. The BBC Master ran fine for… Read more »

The Master is back!

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My BBC Master micro is alive again, thanks to a generous donation. So what was wrong with it before? Buggered if I know. The Beeb suddenly developed a fault a couple of years ago. On powering on, it would show the OS greeting and sometimes the disk filing system greeting but would then hang. I tried a few things but,… Read more »

DottyMatrix: It’s alive!

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My old, beloved Epson MX-80 F/T III dot matrix printer is back in the land of the living. For now. As you can see from some of my earlier posts, I’m designing a serial-to-parallel interface with Centronics compatible DB25 connector so that I can print to my Epson from anything with a TTL serial port, such as a Raspberry Pi…. 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 »

Epson MX-80 Part 3 – well, this is strange

And so to the next instalment of trying to get my Epson MX-80 F/T III dot matrix printer back up and working. Previously on Epson MX-80… Just over a year ago, lots of smoke came out accompanied by a crackling noise. I’ve removed the main smoothing capacitors from the PCB and tested them. They seem fine. I tested the transformer…. Read more »

Epson MX-80 Part 2 – out damn cap

Time for the next step in my attempt to bring my beloved old EpsonMX-80F/T III dot matrix printer back to life. But first, some pictures of gorgeous old retro components. As we’ll see, they might be all I have left. I do love old resistors. They have so much character. And look how thick the wires are. There’s also a… Read more »

Epson MX-80 Part 1 – resurrecting an old friend

It’s hard to lose an old friend with whom you’ve shared more than a  third of a century’s worth of experiences. I’ll never forget the day it happened. I heard a coughing, spluttering noise, turned around and, sure enough, smoke was pouring out of the printer. And not just any old printer – my trusty Epson MX-80F/T III, the first… Read more »

Beeb down…

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Alas, the reconditioned BBC Master Turbo I bought towards the beginning of last year is now sickly. What was a stroll down memory lane has become a project. When I switch on the machine, I get the Acorn MOS message and (usually) the DFS one, but then only a flashing underline cursor. Once or twice I’ve seen more (‘not a… Read more »