Fender Super 210 getting the best of me

[Randall]

Super 210 chassis came in, hacked half to death. Loud sputtering noise, owner attempted to repair it with very crude abilities. Solder blobs everywhere, lots of jumpered burnt traces with flown components. Does it with just the PI and outputs plugged in, so I trace down bad 1/4 watt plate resistor(s). Now it does it with the second pre tube plugged in. OK, maybe more than one problem. Replace those plate resistors. Nope. Tack in new 22uF@500v PS caps, nope. Isolate the noise to between the first and second stages in V102. Ground pin 7 at the first grid, noise stays. Ground pin 2 at the second grid, silence.

One by one I replaced every resistor and cap in the tone stack, which is on the pots panel. Everything from pin 6 to pin 2 has been replaced, and the Dist Vol is removed to eliminate that path. Noise can be eliminated by turning all tone pots down, shunting to ground. See where R15 and the Dist Vol pot tie together, that's on the panel board. The path to the pin 2 grid is a yellow wire running to the main board next to pin 2. Lift one end of the wire, noise goes away since no path to grid. I would have expected to see it on one end or the other, but it disappears. No noise on the grid, no noise on R15. Reconnect R15 to grid pin 2, noise.

I don't understand? BTW, I have repaired the bad "repairs" and then repaired the problems created by all the flexing it takes to work on this poorly designed chassis. Several broken wires and ribbon cable issues. You must remove tubes and flip the board over a little, it won't go far because of the wiring, to change anything out. It's long past being profitable, I just really want to fix it.

[Randall]

replaced all the plate resistors, and butchered tone stack components. That quieted it down by a lot, but still had some other intermittent noises. Resoldered a bunch of stuff, and clipped back and re-stripped a connector wire that was suspect. Put it all back together and it works!

File this one under I don't know, just get it out of here. I suspect it had multiple problems, the original one the guy tried to fix, the ones he created by trying to fix it, and the ones created by repeated flexing and moving while I had it. It also didn't seem to like to have the boards flown while trouble shooting, so there may have been a temporary ground issue as well.

Good riddance!

[Firestorm]

The biggest problem with these amps is that people try to fix them instead of throwing them away, as Fender so obviously intended.

[dobbhill]

If it has ribbon cable, it's disposable.

[Randall]

Yeah... the man who owns the amp is a retired guy who sent a letter with it stating it was his favorite amp. We didn't charge him for all the time I had into it. I stayed with it because I understand where he is coming from, and my primary motivation was to get the man's amp working again. That is what was important to him, and even if he caused most of the damage that I had to correct, he's going to be happy, and that makes me happy.

It's not always about the money. At least from where I sit.

[M Fowler]

The amp will be on Craig's list next week.

I help out guys too, the last two guys I didn't charge but then I'm not trying to make a living repairing amps either.

I got some parts from various TAG members and want to build some 18w amps for local guitar slingers that are down on their luck. Still looking for some candidates.

[Randall]

No chance the amp will be sold. It's the old guy's favorite amp. He's happy now. And so am I.