Fender Red Knob Twin troubleshoot

[guitarlos00]

Hi,

My RK amp was working perfectly and one day I turned it on and nothing. No power at all no lights either. I changed the fuses and the power tubes and still nothing at all. Before I take it to a repairman, I would like to have an idea of what this may be. So if the amp doesn't turn on at all what might it be?

Thanks

[52 Bill]

Welcome to the place. What sort of skills do you have? Do you have a multimeter? The first thing that I would suggest would be the ac cord. Check to see that it has continuity from the plug to the inside circuitry.

[guitarlos00]

I have basic skills (beginner) and I have a multimeter. Ok, I'll check the AC cord and start there. Thanks.

[g1]

There is a second "fail safe" fuse inside the amp. If the main external fuse blows and someone replaces it with a larger one (or tinfoil) the internal fuse will still blow. Was the external fuse you replaced blown? Was it the correct value?

[guitarlos00]

I replaced the fuse on the back of the amp (outside) 7A slo-blow and the inside fuse which is 8A slo-blow. I replaced both of them.

[g1]

Ok, so 52 Bill had said to check your ac cord, and you also want to check the power switch.

[Enzo]

By the way, is the amp pluged directly into the wall outlet? Or are you using an outlet strip?

ANother way: Plug the amp into the wall. Inside the amp, the power cord will be exposed as a white, a black, and a green wire. The green goes to a chassis connections, the white and black should go to the power switch. DO they? Measure AC volts from white to black right on the switch. On the wires from the power cord now, not the other switch wires which may also be white and black. DO you get 120v AC? Not worried if it is 115v or 125v, just want something close, otherwise if we find no volts, then the problem is in the cord.

Now turn the power switch ON. That 120VAC at the switch should nopw appear at the other two wires on the switch. The white wire from the transformer should go directly to the power switch, and the black wire from the transformer should go to the fuse holder. FInd those two wires. Is there 120VAC between them?

[guitarlos00]

I'm a beginner and I'll stop here because I don't know what I'm doing. Wouldn't wanna get shocked or mess up the amp more. When I get the money I'll take it and have it checked and maybe fixed. Thank you for your effort and time.