I had a fun day at work today. Often my work revolves around cleaning and paperwork, with the usual computer issues that need reset or rebooted to be resolved. Occasionally there will be a more complex computer issue with the virtual machine host, or raid arrays if I’m lucky. Today was exceptionally good though, because I had to do some component level board troubleshooting!

Not much to say, since I don’t think I can post any sort of in depth diagram of what I was working on, but we had a unit that had failed, and was supposed to be returned to the depot for repair.

I hate having to send stuff back to depot when I feel confident that we can perform the repair ourselves.

So, with a new employee in tow, we cracked open the case to this unit that is used to split up multiple VGA inputs and apply power over the ZIF (zero insertion force) outputs. A few quick checks with a multi-meter were all we needed to see that power came in, and went to a transformer, a half wave rectifier circuit, smoothed out by a few resistors and capacitors, and then went to a transistor that was a voltage regulator.

Sure enough, it was a L7815acv, which in this case takes a 24v input and gives you a 15v output. The only problem was it only put out 12 volts. Input was plenty strong, with a positive 24 volts, so this was certainly the failure point. We placed one on order, and once it came in we had this unit up and running in no time!

Linux – keep it simple.

[1] https://www.mouser.com/ProductDetail/STMicroelectronics/L7815ACV?qs=Aez0sHNrW%2FWVqGbwZrkJ0w%3D%3DD

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