Hughes and Kettner Switch Blade 50 blowing fuses

[goldtop5]

I have a Hughes and Kettner Switchblade 50 that blows fuses (anode) when turned on and taken off standby. I thought it may have been the power tubes causing it, but it did the same thing when I swapped them out. Anybody hints or ideas?

[g1]

It could be something in the power tube circuitry other than the tubes themselves, like lack of bias voltage or something.
Remove the power tubes and see if the fuse holds.

[Enzo]

If it has flyback diodes, check them.

Measure resistance to ground from the output tube plates, anu show low resistance?

Disconnect the OT, any change?

[goldtop5]

I've contacted product service and support (Yorkville). I was told that the fuse (400mA) was underrated. The tech told me to use either a 600mA or 800mA, or just simply bridge it. I stuck a 1mA in there and so far no problems. For the past couple of days, I did whatever I could to really beat that thing up and it's been good since.

[The Dude]

I've contacted product service and support (Yorkville). I was told that the fuse (400mA) was underrated. The tech told me to use either a 600mA or 800mA, or just simply bridge it. I stuck a 1mA in there and so far no problems. For the past couple of days, I did whatever I could to really beat that thing up and it's been good since.

Did you mean 1A instead of 1mA?

[goldtop5]

Yes. Actually 1000mA. Haha

Did you mean 1A instead of 1mA?