First post, by Alec M
- Rank
- Newbie
About a year ago I inherited a dead IBM 8513 monitor from my aunt.
The issue seemed like it would be a simple fix of resoldering all the commonly troublesome connections such as the AC jack, replace C120 along most of the other capacitors on the power supply, and a few potentially bad diodes.
Unsurprisingly as you may have guessed based on the length or title of this post, this didn't fix the issue I'd been having where when the monitor was turned on it would make a quiet ticking sound with no high voltage, picture, or tube heater.
After a few seconds of being powered off, the power LED would flash for a short time and there would be a squeal from the back. Adjusting the contrast/brightness knobs did nothing.
Today, I decided to pull it out again and work on it, checking more connections and individual components, all of which turned out to be working properly.
Yet again I powered it up just in case my fiddling had helped it. The ticking was still there, but it was more random, and the power LED would still flash and there was still a squeal when powered off.
This time around I narrowed down a hot smell I noticed last time I powered it on to the the posistor that turns off the degaussing circuit, and when I touched it, it was burning hot.
I believe this is how it's supposed to be, but I'm not entirely sure, if someone could back me up on this that would be great.
Just to rule it out as a potential short or power drain, I removed it, since it's only purpose is to eventually turn off the degausser. Doing this did change something, since the ticking was much slower, but there still was no HV, and the same thing occurred with the LED flash and the squeal after the monitor was turned off.
I fear the the only possible thing left that could cause HV not to turn on is the actual flyback transformer, since that provides power for the heater as well as the tube.
However I do think I've seen a very similar model/identical shape of flyback on eBay for around $15 USD.
TL;DR
I've tried a bunch of stuff, it still clicks when turned on, has no picture or high voltage, and the power LED will flash after being turned off for a few seconds accompanied with a short squeal. There aren't any components on either boards that look potentially blown either.
If you have any other suggestions, or know how to fix this specific issue, please let me know. I don't really have any ideas left.
Thanks,
Alec