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Unfortunately Fender does not intend these to be serviced so replacement parts are not generally available from them. That said you can order individual components through suppliers such as Digikey for a reasonable price. No schematics though!
Try disconnecting the load from the power supply by breaking the circuits on both rails. You may need to place a resistor in its place to provide a load on the supply. 100 Ohm 10 W should suffice. Then power up and see if the overheating continues. If not, you may have got a bad IC. If it still overheats the problem is confirmed to be in the supply itself.
power the thing up and monitor individual components in the power supply for overheating. Pay particular attention to electrolytics; they should not get warm in a few minutes. If one does, it may be breaking down / leaky. Replace it. Also watch temps of the regulators on the small heat sinks. warm is OK, hot is a problem. suspect excessive load on the rail associated with that side. It is unusual although not unheard of for the switching circuit itself to be the issue. When they fail they usually just die outright. Beyond that with no schematic it becomes a matter of shotgunning parts. Also inspect the transformer core. If the ferrite core is cracked you may have found your problem. They are critical at the frequencies they switch at.
Unfortunately Fender does not intend these to be serviced so replacement parts are not generally available from them. That said you can order individual components through suppliers such as Digikey for a reasonable price. No schematics though!
Try disconnecting the load from the power supply by breaking the circuits on both rails. You may need to place a resistor in its place to provide a load on the supply. 100 Ohm 10 W should suffice. Then power up and see if the overheating continues. If not, you may have got a bad IC. If it still overheats the problem is confirmed to be in the supply itself.
power the thing up and monitor individual components in the power supply for overheating. Pay particular attention to electrolytics; they should not get warm in a few minutes. If one does, it may be breaking down / leaky. Replace it. Also watch temps of the regulators on the small heat sinks. warm is OK, hot is a problem. suspect excessive load on the rail associated with that side. It is unusual although not unheard of for the switching circuit itself to be the issue. When they fail they usually just die outright. Beyond that with no schematic it becomes a matter of shotgunning parts. Also inspect the transformer core. If the ferrite core is cracked you may have found your problem. They are critical at the frequencies they switch at.
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