Possible Dual-Gang LAR-MAR Pot Issues?

[Rp3703]

So I have a 1959 that I added a PRE-PI master volume and a LAR-MAR POST PI master volume to. While trying work on re-wiring it to run in 2203 mode as well as 1959, I would periodically lose audio all together. While cranking the POST PIMV, I would get the occasional very loud pop. While trying to diagnose my no audio problem for the past two days, I lowered the channel volume and then cranked the Post PIMV and all of a sudden audio reappeared.
My question is, is this a common issue with these kinds of MV's. Is this an issue with Alpha brand dual ganged pots? I know there is another brand that makes these pots, that are supposed to be better in quality but I've also heard this is a bunch of hype.

[PRR]

98:2 odds--- Bad solder joint. Find it. Chopstick.

[Rp3703]

I tried that and got nothing. I’ll keep looking.

[Latole]

Bad solder.

Chopstick don't work all the time

[PRR]

Also dirty tube pins, dirty sockets, dirt in pot wiper, dirt in switching jacks.... it may be a real search.

[Rp3703]

Dirty pot was my original theory since this dual-gang pot has been sitting around for three or four years since I originally purchased it but can a dirty pot or two pots in this case, since this is dual ganged, completely not pass signal while being turned? I've heard scratchy dirty pots but they still passed signal.

[kagliostro]

Jump the pots and see if the problem is still present


Franco

[Rp3703]

Although both halves of the pot are not even(one side measures 250K, the other 210K), there is no point when rotating it that the pot reads no contact.
I am leaning towards another culprit.
I did find a bad solder on my Bias ground but I corrected that and got it to work for a bit but then when I reconfigured it to 2203, I got no signal. Then I put it back in 1959 configuration and still got no signal.
Is it possible for the coupling caps to go bad? I am using a OEM Marshall PCB that I bought used. I read here http://www.geofex.com/ampdbug/coupling.htm that bad coupling caps on preamp tubes can cause zero signal to pass. This amp has the newer cube caps in it.

[Rp3703]

I built a signal tracing probe and signal passes all the way to the dual-gang PPIMV pot and then stops. How the hell is this possible?

[Rp3703]

My PPIMV is wired exactly like the picture below(I used twisted pair rather than shielded cable). When I measure the pot from the center wiper to the output, my measurement goes from 3ohms at all the way down to 206K(outside pot) and 229K(inside pot) at all the way up. I have also confirmed the wire on the output of the pot shows continuity all the way into the bias circuit. How can the pot measure the correct(or close to it) resistance but not pass signal? I'm just worried I'm doing something wrong. Again, this amp and PPIMV has passed signal and the PPIMV worked perfectly. It seems like it always quits on me when I try to rewire the preamp from 1959 to 2203 then when I rewire it back to 1959 it continues to not pass signal.

[shooter]

an actual schematic might help
notes say "notice, no 220k on board", where are they?  did they get changed to 2.2M on the pots?
guessing just gets guesses

[Rp3703]

First off, I need to apologize for my own ignorance all over this thread. There was no signal picked up by the signal tracer on the PPIMV BECAUSE NO SIGNAL GOES THROUGH THE PPMIV! DUH! I'm such an idiot!.
Second, I think the culprit all along may have been my speaker cable. I swapped it out and now I have sound coming from the amp. Thanks to everyone who helped me. I'm sorry I can't give you the time back you wasted on this.

[shooter]

the culprit all along may have been my speaker cable

glad you found it, it's pretty easy to get caught in an endless loop, recognizing you're in one takes experience