Fender Hot Rod Deluxe problem......anyone familiar with it??

[Brad166]

My Hot Rod Deluxe has always had a channel switching problem. Works fine with the footswitch, but without its stuck on "more Drive" Channel.

Anyway the issue is resistor R 97. Its getting very hot. Its starting to brown the PCB it gets so hot. Iv measured it with a multi meter and its value is still in spec. But there is obviusly something wrong. Im good with PTP amps but once I get into these newer PCB amps I get lost easy.

Anyone have a clue?? Need more info???

Thanks for the help!!!!!

[martin manning]

This is a well-known issue. See: http://www.justinholton.com/hotrod/

[Brad166]

Yeah I saw that site. I didnt see anything that applied to my current situation. ITs not channel switching on its own. Its not the issue with the 470 ohm 5w cement resistors if that what your refering too.

Unless im missing something.....

Thanks

[roberto]

The footswitch disables only S2A and S3A, so the problem must be S2A.
Isn't it?

[martin manning]

I read Hot Rod Deluxe, channel switching issue, overheating resistor and immediately thought of the bi-polar power supply resistor problem...

Looking at the schematic, more drive is activated by switch S3A so check that, but also if C49 is shorted that might explain the behavior you are seeing. I believe the resistor R97 is always going to run hot when S2A and S3A are both closed. That might better be a 5W resistor, and elevated from the board.

[Brad166]

The footswitch jack is bad. This is why the channel switching wasnt working. I can push in the tip contact from the back side with my screwdriver tip and it seats correctly and all works. So Ill replace that and channel switching should go back to normal.



But that resistor is still getting super hot. I guess ill replace it with a higher wattage and elevate it off the board. I wouldnt think thats normal.

Thanks so much for all your help and input everyone!!!!!!

[martin manning]

Good work! That was staring us all in the face and no one thought of it. You could pass this one along to J Holton's Unofficial HRD site (link above). Might be useful to other owners.