Marshall TSL100 Issue

[AStacy2]

A friend of mine asked me to re-tube/rebias his amp for him. He bought the tubes and dropped the amp off. After I put the new tubes in the far right power tube won't light up and when I switch to the Crunch channel, there is a weird "fretboard buzz-like" sound coming from it sounds like in the back of the amp?! Any ideas?

 

[ochants76]

Put the old tubes back in and see if it works...If they do then it must be a bad tube. If not..there is probably a more serious issue and you should have it checked out by a tech.
Did you do anything other than change the tubes? Bias adjustments or anything?

 

[AStacy2]

Oh, I forgot to say, it did this before I changed the tubes. That's why I changed them.

 

[ochants76]

Well if it is doing it with the new tubes...you better get it checked out by a tech. Might be a loose wire somewhere...if it was something worse two tubes wouldn't light up I would imagine. In the mean time do not play with it like this. The tubes need each other to push-pull. Without one you burn things up.