Fender Deville resistor burn

[Andrex88]

hello everyone, I would like to ask for help to repair my fender, while I was playing it started to make a smoke and smell of burning, so I turn it off I open the rear panel and I notice that there is the 470ohm 1W carbonized R62 resistor, I manually i am able to replace electronic components, but i would like to understand what caused the resistor to melt. Thankshello everyone, I would like to ask for help to repair my fender, while I was playing it started to make a smoke and smell of burning, so I turn it off I open the rear panel and I notice that there is the 470ohm 1W carbonized R62 resistor, I manually i am able to replace electronic components, but i would like to understand what caused the resistor to melt. Thanks

[xtian]

R62 is a screen resistor, commonly burns when a power tube runs too hot or fails, drawing high current thru the screen grid. Replace power tubes and both 470R screen resistors. Make sure bias is set conservatively when you install new power tubes.

[nevetslab]

And, while you're in there, make a good inspection on the tube PCB's, as I often find solder joint fractures on the tube sockets, sometimes on the ribbons between that board and the main board. A small bright flashlight can illuminate the fractures. On the tube sockets, fractures will usually be a radial ring around the terminal, faint but visible if it's there. Here's some images on the main PCB in a Hot Rod DeVille PCB...on the control pot's solder terminals:



I get the impression you're not an electronics technician, so be aware you're dealing with high voltage in this area. Make sure the AC mains cord is disconnected, and unless you can safely discharge the stored energy in the filter capacitors on the main PCB, there is shock potential for around 10 minutes or more after power had been applied on the amp.

[antrecords]

Yes it's pretty common. One thing, some Fenders have molded speaker cable plugs that go bad, just saw this on a RI SF Deluxe Reverb. Worth checking.

[Andrex88]

thank you very much to all guys, as soon as I start I will update you. Thanks again

[The Dude]

Just a tip: You don't need to remove the entire circuit board for this. Just unsolder the bad resistor, shake it out, and resolder a new resistor on the top side of the board.

[drewl]

You can install them underneath quite easily with needle nose pliers to keep it neat.