fender quad reverb blown, repair help.

[rochotte]

hello, im borrowing a friends fender quad reverb amp. i was playing it, then the volume cut out, it started smoking, and turned off. the fuse was blown, so i replaced it, hopinging that that was all that was wrong. when i turned it back on, it made a hum, then the new fuse burnt. i took the amp out a nd looked at it, but cant tell what part is defective. im thinking it might have been the transformer or power tube, but dont know, and im not very exspirienced in tube amp repairs. nothing looks charred. what do you guess is wrong?
thanks

[Enzo]

Pull the power tubes out and install a new fuse of the proper type and rating. Power up the amp without the power tubes. does the fuse stil blow or not?

Bad power tubes is by far the most common reason for fuses to blow.

Once that test is done, and good tubes are in it, we can determine if the amp was damaged bt failing tubes.

It was probably nothing to do with you. The amp failed while in your care, yes, but not likely your fault. Tubes can fail at any time.

[rochotte]

thanmks for the fast answer, sorry idf my question seemed noobish, but like i said, its not my amp so i havent had to deal with blown tubes.

[Enzo]

I didn't think you were noobish, I was just trying to reassure you that tubes just fail from time to time, and it usually is not because someone did anything wrong.