Hot Rod Mayhem!!!

[GordB]

I am fairly certain now it's the IC. If I decide to order it, I have to wait a week for it as well as the new switch.

Which gives me some time to think about why it stopped working.

These things are pretty delicate.

[GordB]

Found a switch. Replaced the chip in a socket.

Test voltages still out of whack.

I decided to check the diodes in this circuit and found D23 is open.

[g1]

That would sure throw the measurements off. Please post your results after you replace D23.

[GordB]

I've decided to take the amp to a tech. This is work is beyond my skill level. For now.

My thanks to everyone.

[Drewline]

I just came across this thread. We saw a similar problem a while back. One of the relays was stuck internally allowing the master volume to be active in the clean channel setting.

[GordB]

Guys thanks for everything. I wanted to let you know that my hot rod is all fixed and working like new.

But better because everything works. When I first bought it, it was sold new to me by a music store but right there on the showroom floor it didn't switch properly.

Then, it kicked in. Looking back, I should not have bought it as I suspect now it was a return. Maybe.

I took it to a tech and he installed a brand new pcb at a very reasonable price. It is now operating at 100%.

If something goes sideways with it from here on out, I'll take it to a pro.

in the meantime, I'm going to practice on scrapped out pcbs to get my soldering chops up to par.... Thanks