My CT-100 lost HV (from losing one B+ line).

[benman94]

Originally Posted by dtvmcdonald

Bad thoughts. Could it be arcing in the CRT? ....
This has me worried for my 15GP22.

It's a very real possibility, and I'd start looking for ways to rule it out.

My Great-Uncles Neil and Skip told me that the 15GP22 was a notoriously unreliable tube even when they were new. Many of them failed under warranty, costing RCA even more money, with arcing as a primary symptom. That's part (albeit a small part) of the reason that the 21AXP22 was rolled out in late 1954.

That said, I wouldn't worry too much. Tom's scenario sounds the most likely IMHO: all circuits on the +375 rail drawing excessive current with a tiny spike being the straw that breaks the camel's back.