After getting back into the amps I had built a while back, I dusted off my JTM45 and gave her a whirl. In the day it was blowing mains fuses but it seemed work fine. Then a few days later, she started blowing the 2A fuse again, even in standby.

After taking off the back cover I found the OT had leaked wax all over the inside and outside of the chassis. Some wax got into the output tube sockets, which I'm guessing is the main culprit. I'm going to clean everything off but am more curious why the OT got so hot the wax all bled out? What would cause this? Running on the wrong impedance? Tubes biased too hot? etc?

Would it be best to replace this OT?