I had performed at a gig with my two year old Marshall valvestate amp about a week ago and never used it until the weekend on plugging in i found i had no sound? All lights on and the amp doing everything it should but no output of sound? I checked all the usual stuff and nothing was found. However i suspected one of the tubes had gone? I replaced this tube 12AX7EH also known as (ECC83) I was carefull not to touch the glass of the tube so fitted this inside the amp. Switched on and brilliant i had sound once again!!! However i had the amp on for approx 7 mins so while playing the guitar it all went dead again? All lights still on but no sound this has just cost me £13.00 and i suspect the tube has blown again. Can any body tell me what i may have done wrong? was i supposed to have done something before playing the guitar through the amp and putting on the overdrive? Any help please Could this be something else blowing the valve?? I had no tale tale signs something was going to go wrong, no burning smells or no cutting out just went dead.
Probably a bias resistor, or the capacitor in front of it, has gone wonky. Take the amp in for service. At two weeks of age, hopefully they will perform the repair while you wait.
Thankyou for the info i don't know why this post has been repeated? I have since taken the amp to be repaired Uh!!! Repaired its been nowhere. I read some place on the net that this amp is the sort of amp you could throw down the stairs and it would get back up and dust itself down and say "What was that all about"?What a laugh that is!!! This fault i had seems a very unique one as i could find nobody on here who had the same problem i have. Anybody had the same problem please let me know.