Tube DIY Asylum

Posted by caffeinator (A) on May 01, 2020 at 10:00:54

In Reply to: RE: Power transformer troubleshooting - would it short out intermittently? posted by danjf on April 30, 2020 at 16:11:50

The fact that it shorts out with all the tubes removed suggests it may be the power transformer, and perhaps the primary. Since it doesn't do this with the transformer removed, it seems to me the problem might not be the transformer alone, but perhaps the transformer as mounted in the chassis. My thought is a short from a transformer lead to the chassis or ground.

Carefully check the transformer leads, looking for any cracks or brittleness. If they are cloth covered, look for fraying, fuzzing or thinning. Consider wrapping the leads in heat shrink to be sure the insulation is sound. You may want to remove the end bells to trace the leadouts (presuming here that there are leadouts) inside and perform the same inspection and insulation upgrade.

Hope this helps - good luck!