Moreplay left channel crackle then out completely

[dyrstr8s]

My Moreplay, been using with no problems for weeks (months maybe) since upgraded.
Recently had an intermittent crackling, popping in left channel, then it went out completely.
I performed the low voltage test from the upgrade manual. Both sockets measured at 6.27-6.3v.
I performed the high voltage test. Measured 127v at U6, 180v at B+ Reg TP, but less than 1v at U16.
What to check next?
Thank you.

 

[Paul Birkeland]

I would swap tubes just to see if that makes any difference, but you're likely up against a broken wire or a flaky solder joint. The 0V at 16U makes me wonder if the wire connecting from there to the upgrade board is broken.

 

[dyrstr8s]

I just put it away for a while, feeling very frustrated. I just dont understand how something works great for weeks then just stops working.
I checked the voltage at b plate on the board and its the same as 16u, so I dont think its the wire. Saw a transister solder point on the board that seemed lacking solder, tried to touch it up, but my iron touched the 2.2uF/250V capacitor, left a scorch mark. I think I fried it!
Now I get less than 1v at both 6u and 16u.
I think I screwed up the board, I give up, I'm just not cut out for this. I can't solder worth a damn.

 

[Jameson]

Quick story. I assembled a SEX 4 too quickly at our warehouse when I was trying to make some videos for social media and didn't do a great job on a couple solder joints. It worked pretty well for a couple weeks and one day a capacitor blew. Might have been the additional stress from heating up and cooling down, or it might have been degrading the capacitor over time. Don't know. It sat at my apartment for a couple months until we moved into our new house. I revisited with fresh eyes, took my time, and fixed the issue. No problems since then.

Taking a break and coming back to it is a good idea. You could post some photos of underside of the chassis and the board and that could help us point you in the right direction. We can send you replacement parts.

It is rare that someone can't work through a problem. I bet you can. If you can't and you want me to take a look, reach out to me at Jameson (at) Bottlehead (dot) com and we can discuss a repair option.

 

[Larpy]

Have you tried gently poking a chopstick around the left channel's circuitry? The problem has to be there since the right channel is working. Turn the Moreplay's chassis plate over so you can access the circuit and, while the Moreplay is playing music or a test tone from a source into an amp that's driving either speakers or headphones, poke around until you hear noise in the left channel (could be music or crackling). Poke everything in the circuit path. Keep the volume low. Once you find a spot where poking produces a sound in the left channel (likely a solder connection), turn everything off and resolder that connection.

This has worked for me many times over the years. A time or two the problem has been simply a stray piece of wire touching the chassis and shorting the signal to ground.