another DSL100 issue **HELP!!!

[voodooeye]

I have a Marshall DSL100 head I am having some crazy issues with. About a month ago I was playing at our practice site (new place) and all of a sudden the volume just went out. I noticed that my effects loop wasn't receiving a signal either so I unplugged the effects loop but still nothing. I powered the head down and ran the power to another outlet. I powered the amp back up and everything worked again but everything was a little fuzzy and the volume wasn't quite up to normal. The next day, I played through it again at home and everything worked fine. I played a few days later at the practice spot again and everything worked fine for about ten minutes and then I had a repeat, volume cuts out and after about five or ten minutes it comes back, a little fuzzy at first but then is totally fine after playing for a couple of more minutes. I was thinking it might be the power or preamp tubes so I replaced them all and rebiased the power tubes. To no avail, still having the same issue. I've tried just running the guitar straight into the head with no effects, different chords, no effects loop hook or anything and the problem still happens.

Here's the symptons in a nutshell;
*volume cuts off after being played for about ten minutes
*no signal goes through the effects loop
*no hum or hiss out of the cabinet
*after a few minutes the volume slowly returns, fuzzy and distorted at first
*after a few more minutes of playing the volume fully returns and the problem does not occur anymore while the amp is on, or even while it is still warm and power back on

Any thoughts or suggestions would be greatly appreciated!!! I am taking to a tech tomorrow but wanted to see what others may have experienced or what it might be.

thanks!!!

[Valvehead]

im thinking a bad solder joint in the preamp area-or a loose cable?

[voodooeye]

turns out that a resistor had gone bad and in turn messed up a couple of the tubes. new resistor and new power tubes.

[drewl]

Good for you.....

[Amp Kat]

As a precaution for the future be real conscious about those power tubes when they start wearing. Loss of volume or treble or good signs they are going out and for some reason this amp has ill effects of worn out tubes. It can get much worst than yours was in a flash of a second.

[voodooeye]

it's been a while since i posted regarding this amp, but my problem still remains. I have been to three different techs and all of them have tried different things only to conclude they can't figure it out and marshall tells me to keep taking it to one of their service centers (which are the some of the techs who can't figure it out). The pre and power tubes have been replaced, most of the resistors, some capacitors, the bridge rectifier and have had all of the solder points retouched. Marshall won't do anything about it and it is still under warranty.

I am at a loss as to what to do. It will get extremely hot, to the point to where the handle on top cannot be touched. the back grill will blister your skin if you just barely touch it. after a few minutes of playing the tone will start to very between dull and bright and the volume will eventually fade away. after about five minutes the volume will slowly swell back on. after another minute or two of playing it will fade away again. it will keep repeating this cycle. On a couple of occasions you could smell the board or something burning. Marshall won't do anything about, the techs can't figure it out, and I'm out $1200 on a POS amp. an ongoing issue for a year now and it fails at every show and practice.

Does anyone know of a contact with Marshall that I can voice my concern to? this head needs to be replaced period. if the techs through marshall can't figure it out, then i'm not sure who could. the labor warranty period is over, so every time it goes in i'm paying for labor.

any advice would be greatly appreciated.

[Valvehead]

At this point , what I would do, is replace the OT . Those dsl/ tsl trans are not the greatest.
I would stick a Heyboer trans in it and try it .

The OT going out usually will not blow fuses.

when it gets hot , put your finger on the OT and then the PT , is either getting real hot?



Have you measured voltages with the amp open ---right when it starts fading out and acting up ?


If it was the PT , i would guess it would get hot itself and take out a fuse. But , an OT going away is WAY more common than a PT .

[Amp Kat]

I think you just need the the right tech. Are you in the states ? Maybe we can get you fixed up with someone we know or can recommend. I would change that rectifier no matter what not just touch solder joints on it. Sounds like the heaters are dropping out then coming back up.

[Enzo]

Me too, are you in the USA? When yuo say "marshall told you..." just who did you contact? Marshall amps in the UK? Or KorgUSA in New York, the USA distributor of MArshall products. Korg would be your contact for this.

Do you have a record of your repairs? Korg should have a repair history on the unit from their warranty center claims at least. Either way, if there is a history on this same problem, the warranty SHOULD cover it. You got an amp with a problem, repair was attempted several times but was not effective, so the problem still exists. SO the repair was essentially never made. Credit the techs for making a good faith effort, but they never fixed it. Warranty can expire, but if the amp is still under repair, then they don't get a get out of jail free card and a "whoops, time's up."

Be nice, but be firm: you bought an amp that has never been right, and you want them to make it right. Talk to Korg customer service and tell your story, you've been bounced tech to tech and no one can striaghten out the amp. What wil they do to make your puchase right? If it takes shipping the amp somewhere, so be it, ask for a call tag be sent.

[Pedro Vecino]

Sounds like the heaters are dropping out then coming back up.

Yes. Check if the tubes glow or they get dark when the effect happens

[drewl]

I had a "boomerang" like that in which the bias board resistors were intermittant causing the bias to go crazy once in a while. FYI.

[voodooeye]

I took it back to the most recent tech. he is working with marshall to try to get it straightened out.
I'm located in cincinnati, ohio. i believe it was the korg guys i talked to.

[voodooeye]

latest update: The authorized Marshall service center could not figure it out. I sent a letter to Marshall's customer service, which turns out goes to Korg. I received email correspondence from them stating that they are going to replace the amp. I contacted the tech and he informed me that Korg/Marshall contacted him and was sending RA# to him for return. Once they receive the head they are going to send me a replacement. When i receive the new head i will post back.

[voodooeye]

It's been a while but the issue is finally resolved. After haggling with Marshall (Korg), they paid to have it shipped back to them. They received it, couldn't figure it out and shipped a brand new JCM2000 DSL100 head to me. It took so long to get this whole problem resolved, i could have bought another head just with the amounts i paid for rentals and labor repairs on the old head. While i truly am a fan of the marshall tone, i will most likely never buy another marshall product. too many reliability problems, customer service got pretty crappy with me in emails, and it took almost a year from the first symptom to the delivery of the new head. At least i got a new head.

[izzybell2810]

It's been a while but the issue is finally resolved. After haggling with Marshall (Korg), they paid to have it shipped back to them. They received it, couldn't figure it out and shipped a brand new JCM2000 DSL100 head to me. It took so long to get this whole problem resolved, i could have bought another head just with the amounts i paid for rentals and labor repairs on the old head. While i truly am a fan of the marshall tone, i will most likely never buy another marshall product. too many reliability problems, customer service got pretty crappy with me in emails, and it took almost a year from the first symptom to the delivery of the new head. At least i got a new head.

If you get any probs with this new marshall, my advice would be to e-mail Marshall direct here in the UK. I have always found them to be most helpful! In fact some years ago I had a guy bring in a Valevestate power amp that had been completely fried to the point it had set on fire and components were just un recognizable. This was caused by a faulty on /off switch, the guy had unplugged the speaker leads with the amp turned on and one of them shorted on the flight case the next thing he knew there was flames coming out of the vent. He needed the amp the next day I called marshall they faxed a schem to me (This was before the days of e-mail) and I told them exactly which components I needed and they couriered them to me free of charge along with a new power switch.