Marshall DSL100HR Keeps Blowing Fuses - Tales From The Repair Bench

[@richardweza3369]

Tinnitus after a concert without ear plugs. Awesome analogy. Props from a new Yank subscriber.

[@scalzittiluthieria6452]

Just discovered your channel! Awesome Work. Very Nice Video Quality and explanation

[@drgearaustralia]

Thanks! We’ve got more in the pipeline including instrument repairs and more as we do more than just amps.

[@Happy_Broom]

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.

[@simonkormendy849]

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.

[@richinderbyshire4779]

Cheers for the vid. Dr.

[@ianstrickland5280]

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.

[@drgearaustralia]

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.

[@gedification]

Nice work.

[@bobroszkowski]

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.

[@drgearaustralia]

Use the parametric search function through Mouser/Digikey/Farnell and there should be some at one of them.

[@bobroszkowski]

@@drgearaustralia Thanks! Were you able to use the snap in?

[@zbaby82]

Good job!

[@seanlandis9482]

I have that same 720hz noise coming from the amp but the volume seems normal. I just got it new so I’m a little concerned. Anyone else have that?

[@Shadowsreach1]

cool video!

[@zandig666]

Hi bud can you do a video on the standby switch there's not a lot of definitive info about its proper use if any 🤟🤟

[@drgearaustralia]

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.

[@dstroyer7306]

If you mind me asking, how much did this repair run for? I believe I’m having the same issue with mine.

[@drgearaustralia]

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.

[@diyautosolutions1960]

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?

[@drgearaustralia]

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.

[@diyautosolutions1960]

@drgearaustralia funny because I found that 2 of the .5w 1m ohm resistors in the resonance circuit were the issue not tubes..

[@zandig666]

This is porn !! Lol I have the dsL20h bud, with only 1vol and gain is that volume a master volume ?? 🤟🤟

[@drgearaustralia]

The DSL20H has the same control layout for the most part as the DSL100HR. So gain and volume for each channel with a shared EQ.

[@simonkormendy849]

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.

[@drgearaustralia]

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.