My Mark III just blew a resistor!

[SonicProvocateur]

Yesterday I replaced the my Mesa 5881's to EH 6L6GCs for some extra gain, and today I fired her up and was doing some tone tweaking and after about 20 minutes of playing, there was a little noise, and I look over and see one of the power tubes sparkling like mad as the tube blowing, hear the tube blowing sounds (the light hissing and popping sounds) and I run to hit the standby switch, and as I'm trying to flip it, I see smoke and the unit turns off...

!#&*

So I turn the power switch off, unhook everything, a little more smoke, and after a thorough inspection; the only damage is a toasted resistor on one of the power tubes (whew). The fuse didn't appear to be blown, but look slightly burnt near the bottom. I call the previous owner (also my ex-coworker and Boogie dealer) and hopefully we should have it running again soon...

Guess age and high gain takes it's toll eh? Any diagnosis experts?

 

[Boogiebabies]

It's a common occurrence with todays tubes. The inner screen resistors are 470 Ohm and should be upgraded to 3 watt.

 

[238839]

Same thing happened to my 1986 Black Stripe. When I replaced the power tubes after a few years of use, my Mark III smoked the new tubes in about 10 minutes. Called Boogie...they asked what was my serial number..."OH-you have one of the older Boogies...the bias resistor isn't compatible with the newer type tubes used today" Changed the bias resistor which helped alot but it still smoked power tubes every month or so.