Fender Rumble 25 lost power

[heave1]

My Fender Rumble 25 suddenly lost all power. Checked the power cord and on/off and power receptacle and they both have power. None of the test points show any voltage so I figure it's something on the PCB. What resistors or caps should I check? I know it's a cheap amp, but I would like to know why it lost power.

 

[heave1]

I found the problem, a blown resistor on the bottom of the power board. It is marked as R309 and it looks like when it blew, it destroyed the trace. Any ideas on how to replace R309 and repair the trace?

 

[JakobT]

I would advise against trying to fix this yourself. Take it to a Fender Authorised Service Center.

 

[agedhorse]

WHY might the resistor have blown like that.

Answer... because of an additional failure that caused high current.

 

[heave1]

It's just not worth the trouble. I really need a schematic, but I can't find one anywhere that matches my version. The only thing I can figure is a power surge? It was working when I sold it to a guy who then brought it back claiming I sold him a bad amp. He's lying because it was working when he got it and the amp came back with a blown resistor. I think I will just use the cabinet to make a combo or speaker cab. Thanks anyway.

 

[agedhorse]

Rarely a "power surge", maybe not even something that the buyer even did to it. Sometimes failures just happen. A qualified service tech shouldn't have any difficulty repairing it, but because you have R309 this indicates that it's an SMPS (later version) which is generally not economical for an average tech to repair, and I don't recall this SMPS being available as a replaceable part as it was less expensive to replace the entire chassis.

 

[heave1]

It's not worth it. I am going to use the cabinet for either a speaker cab or a new amp build. Thanks for the help.

 

[butterfingers1]

Two years ago my Rumble 200 died, fried electronics, still under warranty, Fender replaced it. It took 6 months though.