Re: 7904 Mainframe damaged


 

If they all read high in resistance, then a likely reason is that they're cold. If it was one or two...but all of them ?

There is still probably something wrong right in that power supply. Not sure exactly what to check next right now, I have other things on my mind. (court case in about an hour) Later on I will review all the information and try to come up with something helpful.

Remember test lights ? An incandescent that you wire in lieu of a blown fuse. It limits damage and lights up when there is a short. You start unplugging things until the light goes out and there's the short. Well there are other uses. you could use it as a dummy load for the power supply. Any source up to about 130 volts can be loaded and a 100 watt will pull about 1 amp. That should keep it down so it regulates. I have one of those emergency lights electricians use but you can just take a couple of test leads to the plug on a table lamp or something, The only thing is that is must be an incandescent and they are getting a bit scarce, in California especially. But a CFL or LED won't work right for this purpose. And using a transformer and a car headlight or something like that won't work for DC. A simple old fashioned 75 or even 60 watt bulb will do the trick.

Then the power supply should run without being connected to the rest of it, which I am sure will make any live tests easier. (or possible at all)

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