Fender 100 bassman combo faulty - help needed

[krispn]

My buddy has a Bassman 100 combo, one of the newer little fellows.
He has been reporting a fault with it, basically a crackling sound which he thinks is from the tweeter.

Has anyone else experienced this issue with these amps and does it sound like a simple repair? I'm not usually one to hunt down fixer amps but this seems like a decent wee amp for little money if the repair isn't too costly.

Cheers for any help.

Oh and I'm gonna try and get my hands on it next week so I'll try and get an audio sample!