Thanks for the video. Customer dropped off same amp/problem here. Having a hard time finding the big filter caps. Can you tell me where you found replacements? (220uf/315v C21,C22, 220uf/400v,C19,330uf/315v,C13,C14) 40mm is the max height.
Resistors 8 and 9 are in direct contact with the trace going from C 24/ R 49 to R 11. Heating and cooling or arcing can break thru the insulation causing a direct short between R 8 and R 9 and the trace in turn shorting C 21 and/or C 22 to the trace. Smokes R 49 when switched to low power. Design flaw! Lifting R 8 and R 9 away from the trace solves/prevents the problem.
guitarist in my band has this amp, literally exactly the same issue, master volume cranked and its output is ungodly low. even when on and cranked, it still sometimes makes no sound at all.
Then it’s possibly having the same issues as this one. The high/low power circuit uses two different power rails for the output section and if one goes short as happened to this amp, you get no voltage where it needs to be. Time to take it to a tech for assessment.
It’s a whole board out job which takes a bit of time. I think top to bottom it was about 3 hours to replace all the caps, rebias, burn in and all that.
I got the same head in a trade, it seems to work fine minus it has a noise when powerd on the speakers sound like a mild burning fire noise or the sound of the ocean kind of static. It's not loud but noticeable. I've replaced the preamp and power tubes and biased at 73mv per side the sound is still there. Is this normal for this amp or do you know of this issue?
You can’t bias a set of tubes with a random static value like millivolts dropped across a cathode resistor. These are complex amps and there are a number of things that can cause this issue which requires a strong understanding of trouble shooting.
Probably get around to doing one at some point, but in the meantime if you jump onto the Psionic Audio channel, I’m pretty sure he’s done a good explainer on them and how many companies don’t actually implement them well.
And I'll bet that the cause of the fuse blowing is the dreaded conductive PCB syndrome that some of these Marshall DSL series amps tend to suffer from.
And I'll bet that the cause of the fuse blowing is the dreaded conductive PCB syndrome that some of these Marshall DSL series amps tend to suffer from.
What? If you watched the video you’d know the issue was shorted power caps. These new Asian made models are made in an entirely different factory using different board fabricators.
