Power Tube Melted Down and Hoping Amp Is Not Damaged?

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John 14:6

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I have a Friedman Small Box and today I lost sound with the band. I went to check the amp head and could smell a faint burning smell and turned it off. The problem is I finished playing the song even though I had no sound before turning the amp off. When I got it home, I went to troubleshoot it and the red power light did not come on.

After taking off the back panel I found one of the power tubes had melted. It had cracks and a big dent where the glass melted, and metal is now sticking through. The silver on top of the tube is all white colored now. I ordered new tubes which should be here this week. I am hoping that the amp did not get any components damaged. The tube socket shows no burn marks and looks normal, so I am hoping that is positive sign? I have never had a tube do something like this before. I have a Weber Bias-Rite plan to try fixing it myself before going to a tech. Any thoughts or advice?
 
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Replace tubes and replace blown fuse.
Should remedy the problem.
Never heard of a tube melting before.
Just curious, what tubes were in the amp?
 
Remove tubes and replace fuses. Power up with correct speaker load . If fuses don't blow, then power down, install tubes and power up. If you don't know the ma rating of the new tubes, back off bias reading at pin 5 to - 45/50 V . Check the screen resistors before power up. Email Dave. He's very helpful.
 
Rocker68 said:
Remove tubes and replace fuses. Power up with correct speaker load . If fuses don't blow, then power down, install tubes and power up. If you don't know the ma rating of the new tubes, back off bias reading at pin 5 to - 45/50 V . Check the screen resistors before power up. Email Dave. He's very helpful.
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This. Check screen grid resistors and contact Dave. Hopefully all HT and Mains fuses did their job and protected the rest of the circuit but you never know. I personally would not just drop new power tubes in and hope for the best. I also have never heard of a power tube melting to this extent. What kind of tubes were they and can you take some pics?

Sorry man. :(
 
Another vote for checking the screen resistors. A buddy's amp had a very similar thing happen except the tube didn't melt, and the screen resistors were cooked to the point of failure. One opened, the other read high by 20%, and the board itself was black, possibly de-laminating, and soldermask and pads were lifting.
 
Holy shit, I’ve blown tubes before but I’ve never seen one melt!
 
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