[Amps] Final Ck out of 8877 Amp - Help Pse

[zilassoc@sbcglobal.net]

I accidentially over loaded my Henry 4K with too much RF drive and tripped 
the main cirucit breaker.  After resetting the breaker, I applied HV in 
standby (ie. without keying the amp) and blew the breaker again.    Upon 
troubleshooting I noticed I had to disconnect the B+ from the 8877 anode in 
order to get the HV power supply B+ to come up and not blow the breaker .  I 
have to assume the 8877 has failed.   Is it normal for the 8877 to fail and 
short B+?  I measured the tube anode resistance (with a VOM) to the various 
pins, but observed no continuity (I don't have a Hipot Tester).  What should 
I check or do before I open up my spare EIMAC 8877 sealed box and install a 
brand new 8877?  I would hate to fry a factory fresh tube because I failed 
to check something in the amp before installing the new tube.  Any 
suggestions what I should check?
Thanks,
Pete, K5PZ