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My valve Jr stopped working.


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Playing away and suddenly the volume peters out to nothing. Power light still on.

Not knowing much (anything) about tube amps, I had a look at the valves and could see no glowing. From this I assumed the valves had died.

I purchased a new set, and when they arrived very gingerly set about installing them. After what seemed like ages I managed to get the back panel off and very carefully replaced both tubes. Replaced the back panel and switched it on, but there is still nothing - no sound at all, no glowing tubes. The old tubes seem to be fully intact.

Local techs want to charge a fee simply to look at it, then charge for any work carried out. I'd like to at least know if there's anything that I can safely check before going that route - I'd be a might peeved if it turned out to be something simple I could have fixed myself.

I've done a bit of reading about tube amps and am wary about poking around inside. Is there anything I can check myself without putting myself in undue danger?


It's a version 3 combo.



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Check the fuses. The power light is on, so that means the mains fuse (2a-250v) hidden inside the power cord jack is good. But no filament glow in the tubes says the heater fuse is blown. That one's 4a-250v, and it's in the fuse holder on the orange wire underneath your power transformer.


Pull the fuse, and check it with a meter. Then push the wire up through the fuse holder and buff the varnish off the contact pads. Reinsert fuse and crank it up! This has been a problem common to all versions of the VJr.



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It was even simpler than that - the heater fuse holder had popped apart. I don't know why, but it doesn't appear to have the shoulder on the bottom section that slides into the top section to keep it together, so it is using pressure alone. It had come apart just far enough that the fuse wasn't touching the top contact.

Well, that saved me some £30, so thanks again!

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