Peavey output choke resistor is burning

[mindofone]

I’ve got a very nice, very old Peavey 300 amp from 1971 or thereabouts. The amp works, sounds good. However, it seems to have a penchant for burning up the 22 ohm resistor that sits across the output choke assembly (circles in red in the attached schematic.

I am wondering if the choke could be shorted and causing the resistor to burn? Other suggestions? Might be time to break out the dick smith flyback tester!

TIA.

[Jazz P Bass]

Have you resoldered the inductor to the board?

[mindofone]

Sneaky bad solder joint on one leg of the choke. Desoldered, resoldered, and seems to now work flawlessly. I get the impression this amp has been jostled around the country a few times.

Thanks!

[Enzo]

Follow how a shorted coil could never burn up that resistor. No current could flow through the resistor.

Solder joints do break, but rare as failures there may be, I find more of them as a broken wire on one end of the coil. Easily repaired though.

With a broken or unsoldered coil then ALL speaker current must flow through the resistor, which quickly burns up.