Loss of power on Mark IV

[Calidcaraz]

I have a Mark IV combo that I have had stored away for several months. Today when I took it out and plugged it in - I had it on standby with the power switch on tweed. After letting it warm up, I switched to Full Power and lost all power. Can someone point me the the probable cause???

 

[Tuna141]

I'd start with checking the fuse and looking for a bad power tube. Check the fuse and replace if blown, then try running the amp in Class A so only one pair of the power tubes are on (the inner pair). If it is a bad tube, this will help you identify which pair/one.

 

[Tuna141]

class A = outer tubes only. Try it with a bias rite if you don't believe me...

Oh I believe you...thanks for correcting my mistake....I just had a brain fart. :wink: