please need help with mesa f-100 combo

[yngwie1993]

just bought a mesa f-100 combo(2 years old) and the amp is making a big popping sound,very loud when i switch to standby mode even when i turn off the power switch (sound like a real explosion,i m affraid of busting the speakers)i took a look and every tubes lights up,that noise happen also if all the settings on the amp are at zero and the fuse is not blow...
please can someone help me,it would be really appreciate,thanks!

 

[no soul]

mine pops when I switch it over, most amps have some sort of pop, but if yours is beyond the normal one, its hard to diagnose over the net..

 

[yngwie1993]

is it possible the power tubes 6l6 are defect even if they light-up :?:

 

[Surfcaster]

Yes, just because it lights up doesn't mean it's all okay. Check carefully to see if there are any cracks in the glass. You can also tap the power tubes lightly with a pencil with the amp turned on and standby on...hearing a small noise through the speaker is okay, but if that produces a loud noise, then chances are something is wrong with that tube.

 

[gsouth]

I suggest calling Mesa's support line and have them help you diagnois the problem

 

[yngwie1993]

the problem seem to be fixed,i have change all the tubes this morning and there is no more noise,thanks to all of you for your help!