Need help Bugera 6260 head hum problem

[Rockman1266]

Hi every one I am new here and I need some amp tech help the molex connector burned up on this thing like all the others but when i got it back from the repair shop it has a hum and then the bias resister went out and he fixed that now the guy at the shop don't wont to mess with it and I know a little bit about amp stuff there was all so a cold solder joint or 2 on the v5 preamp tube socket I repaired that and why I was at it went over all the solder joints and stuff I have changed all the tubes re biased all the stuff you would think it could be this hum is there with no guitar plugged in and all the controls up or down it stays the same the only time I can here it get different is when you adjust the bias on it so any help you guys can give me I will take.

[The Dude]

Welcome to the place!

Not to start off on a bad foot, but according to the typing police, it's much easier to read threads when punctuation and capitalization is present.

Hum can be difficult to track down, especially if you don't own a scope, which I'm betting you don't. Also note that tube amps contain very high and dangerous voltages, so be careful! My best guess is that you have a bad filter cap or one that's not soldered in any more. I'm a bit surprised that your tech is refusing to work on the amp when he apparently hasn't got it right yet. Saying that we may not know the entire story, so I'll reserve judgment on my opinion of him.

Some things to check:

1) Check for AC on you B+ and bias lines.
2) Make sure caps are not loose and soldered in well.
3) Pull preamp tubes and power up. Is the hum still there?

[Rockman1266]

Hum is still there after removing pre amp tubes. All solder joints are good and no missing caps. how do I check for AC on bias lines what is B+.