A while ago, I was given a 'Fakerscope' which is a handy device for intercepting and decoding RS232 communications. It actually does much more than that but that's for another post. It worked fine for a while and helped me out a bit with the Oval serial display adaptor (although I eventually did RTFM).
But all of a sudden, the display stopped working. It was blank, and no amount of fiddling or switching on or off would solve it.
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| It's worse than that, he's dead, Jim. |
So I took it apart and found that, even though the battery had been removed by the previous owner, the capacitors on the display had some corrosion and, as it turned out, several of them had leaked too. At the time I didn't have any 10uf 50v caps so I ordered some and put the pieces of the 'scope away. And there they stayed for about eight months.
So tonight I fished out all the parts and screws, and dug out the long since received caps.
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| Bag 'o bits. |
I'd removed the caps but some corrosion was still on the pads so it took a few minutes to get them into a state where they were nice and shiny. The fishy smell from the pads confirmed the leaky cap theory. Six caps were duly replaced.
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| Note the artistic folding of legs on the radial caps. :) |
Putting everything back together was a bit more involved than I thought. I'd managed to lose some of the plastic spacers on the screws that held the screen to the top of the case. And I'd forgotten that some of the screws were horrendously tight and the heads had been damaged when I removed them. And I realised I'd lost the screws for case.. I really done gone messed up on this one chief.
Hunting through my spare screw box, I managed to get enough screws the right length and pitch so I thought I was ready to go.
But.
After connecting everything together the display didn't work. Then it started to make clicking noises. Hmm. Best switch that off...
One tiny detail I'd forgotten; the cable that connects the display has a red line on pin 1. Except it isn't. Yes, the cable is, to any sane person, the wrong way around. From factory. Which I forgot. Doh.
Fortunately, no damage was done and as soon as I switched the cable, it sprang back into life. Yay!
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| Nice, proper display. Nice. |
So, this was a rare case where changing the caps DID repair the fault. Yay!
