My H.T. Fuse Keeps Blowing In My JMP 2204

[marshallman116]

It is happening very frequently and I need a solution.

Thanks

 

[Micky]

Can you provide more info?
Like:
Does it do it with your spare set of tubes?
What is your bias set to?
What size fuse does it call for?
What fuse are you putting in it?
Any mods in the amp?
What speaker are you using and what ohm settings on the amp/cab?

 

[marshallman116]

I haven't tested it with a spare set of tubes, I don't know the bias. I'd have to call my amp guy. It calls for Half Amp slow blow and that's what I put in. The only mods are EL-34's and I took the bright cap out. I'm running two 16 ohm cabs and have it set to 8 ohms but it also does this with one cab and on 16 ohms.

 

[mickeydg5]

Hi MarshallMan116

It is most likely a power tube issue. Turn the amplifier OFF and pull the power tubes. Replace the fuse with a good one. Turn it ON and power on STANDBY. Did the fuse blow again? If so then there are other issues besides power tubes.

Either way it will need a technician to start checking for correct voltages and shorts or bad components.

 

[bulldozer1984]

Most likely power tubes. If it still blows after that then its tech time.

Last time that happened to me a bad tube took out a grid resistor.

 

[marshallman116]

It doesn't happen immedietly, it's periodicly but I feel it shouldn't be that frequent.