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Blues Custom 30 problems

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Looking at a Blues Custom 30 for a friend.  His complaint was that it wouldnt power on.  I checked all internal fuses and HT fuse (good) but the mains was blown.  Replaced the mains fuse and it powered on normally and went off standby normally but had no sound.  I pulled the tubes to inspect and the phase inverter tube had lost vacuum (white flaky getter).  I ordered a 12at7 after reading up on phase inverter tubes this amp and after replacing it the sound returned and everything worked great but no reverb.  I tried another 12ax7 tube I had in V3 and V5 but they didnt help.  A few hours later I tried the amp again and noticed a blue spark when going off standby in the V8 rectifier tube.  I plugged it into a dim bulb tester and intermittently going off of standby causes a brighter bulb while other times it acts normally.

I am new to tube amps so I checked the reverb transformer looking for a possible short and the secondary seems low on a resistance check (1.2 ohms) but I am unsure of what a normal resistance would be.  Does this sound like a shorted transformer secondary or has anyone else had a similar issue?

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