a bit of help please

[mkstylee]

hi all having a bit of hassle with my 4100DR ,it's going to marshall for a service as soon as i can fund it ,but today when playing i kicked in a tube screamer and the sound went real quiet ,i disengaged the pedal and the sound slowley crept back up ,i tried a few pedals and it did the same ,it was as if the amp was overloading ,and shutting it's self down a bit ,thats the only way i can discribe it,is this a known thing so i can get it working till service time.cheers

-- Tue Jan 24, 2012 11:20 pm --

c'mon guys ,what is it? ,pre or power valve? something else just give me a direction
steve any thoughts?

[JCM900MkIII]

I'm not a tech, but checking the pre amp tubes would be easy. If you have a spare/new one that is.

Other than that, I can't be of any more assistance.

Never had an issue like that with my 900 MkIII though.

[mkstylee]

thanks for the tip someone else over on the marshall forum said the same, changed all the pre tubes so i'll just have to see when i try it again ,

[Mats A]

You can try just changing their place also.