• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Troubleshooting help for a neophyte

I have Gabe's Mag 1515 PP kit amp which is no longer supported.

One day it just blew the fuse immediately on start up. I did contact Gabe and he said that it sounded like a bad cap and that I should replace the electrolytic caps.

I finally have gotten some time to get the parts and try to fix this thing. Tried what he said. Didn't work. Tried another rectifier for the heaters - no change. There are two diodes in the high voltage supply section, I slapped the DVM on them and the readings are not making any sense. I will probably have to disconnect them to test them properly, so I might as well replace them since they are pretty cheap.

The one thing I did do is I put the DVM on some of the windings of the Power Transformer, the input side showed resistance as did the high voltage section. The heater supply (6.3 volt windings) showed nearly zero ohms. Is this indicating a short? Is this Power Transformer bad? It is a Hammond 273BX. How would I confirm that the Power Transformer is bad? When i changed out the cap on the heater section I noticed that the end was slightly bulged and the plastic disc on the end fell off.

I am pretty much of a neophyte with electronics. I have done a lot of fabrication in the past but I am not up on my electronics knowledge.

Any assistance would be greatly appreciated.
 
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