Hello, Marshall DSL 40C issue

[Highroller54]

Hello everyone,

Nice forum glad to find it and meet everyone. I have been playing on and off for 40 years. Was on the road for a few years and have owned pretty much every Marshall you can think of at one time or another. At one time I had 15 Heads and 20 cabs in my collection. Now days I have just one Les paul and one 70's small box 50 watter. The amp I using now is a DSL 40C much small and easy to tote when needed. Well I purchased this amp 6 weeks ago and it has been fine until yesterday. Yesterday I fired the amp up and when I turned the standby on, I had no sound

I checked cables and all the normal stuff and zippo, nothing, I then started messing with the amp controls and noticed if I cracked up the volume I would start to get some volume, at around 8 the volume was about a low bedroom level, and on 10 it was even louder but still bedroom type level.

I played with all the controls and noticed that everything seemed to work OK and the amp sounds fine just at a very low level. Here is what I have checked so far.

Cables and connection-No change
Different Guitar - No change
Different amp channel - No change
Guitar directly into the return on the effects loop - No Sound
Reseated all tubes - No change
All tubes seem to be glowing normally, nothing out of the ordinary color wise or temp.
No burned or burning smell - haven't done anything to let the smoke out and didn't notice any at any time.
turned amp on and off multiple times.
With amp running, tapped each tube with a wood pencil no abnormal noises.
amp didn't before or now make any odd noises, cracks, pops or whisels.
No abnormal hum..

One thing I though about, a couple times in the last week for a very brief time, the amp seemed to get overly bright and gritty, but just for a moment or two, I actually thought it was me, but now that I think about it, it was the amp, and one other time the amp had a very suttle almost not noticable loss of low end, very brief. Until Monday morning I won't have any tubes too try trouble shooting with, but all the before mentioned symtoms sorta leads me to believe the OT may have went south. I have already contacted where I purchased the amp and it's over thier 30 day return policy, so if I with the help of forums can't figure this out on my own I stuck shipping it off to some repair dude I know nothing about. I would rather ship it all the way to Florida to an amp tech I know than do that, but the amp is practically brand new and a warranty issue.

Any Ideas guys...?

[Phil_S]

You should see if they will make an exchange under the warranty. If it was mine, I'd want to exhaust the warranty options before I shipped it somewhere. I wouldn't be too concerned about who the warranty tech is and I'd assume he's competent until I found out otherwise. There is little mileage in giving work to people who can't get the job done. Amp fixing isn't rocket science. Really, it is pretty basic electronics.

[Highroller54]

Problem solved!



I contunued to check things, and decided to check more into the effects loop. Plug a cable as a jumper into the loop and nothing, engaged the on/off switch for the loop nothing but I did get a pop. Hit a chord on my guitar and cycled the switch and boom the amp roared to life, scared the crap out of me, due to the fact I had it on 10 so I could here the guitar. Not sure if there is a permenant issue or if the loop switch wasn't making good contact, but everything seems to be working fine now. This is a push button type switch just like the channel and gain mode switches on the front of the amp. If it happens again I will look deeper into the switch issue and clean it and reheat the solder joints. Thanks Guys for the suggestions.

[Phil_S]

Effects loops are a common problem. Buy a can of contact cleaner. Spray the jacks and run a plug in and out of there several times. I can see the problem returning. No abrasives -- they remove the plating on the jack contacts.