#1
Hello, I just recently bought a Marshall JCM 2000 DSL 100 from a 2nd hand store. When i tested it in the store it worked fine and when i got it home i suddenly got no sound. It gets full power and all the tubes are working. And I've also replaced the HT Fuse because it had blown. The strange part is when the standby switch is set in the "ON" position i can hear my guitar but it is very faint. When it's set to the "OFF" position i get nothing. If you have any information that might help I'd be very greatful. Thank you
#2
Mine did the same thing. it is a problem the earlier DSL's had with over heating. I blew a cap in the PCB of the power section (and it blew a tube also). I had to have a trace from the PCB removed and hardwired in place and a new set of power tubes.

I really lucked out because my brother works on amps so my cost was $80 for a set of used SED tubes he had, the rest he did for free. He told me it was easy a $300+ fix at a normal repair place (that's all parts and labor).

Mine has been fine for over a year now, but it will cost you some money to have it fixed unless you know someone who is good with PCB's.

Sorry to be the guy to give you bad news

EDIT: always turn the amp when not playing because of the overheating that can happen. Don't leave it on standby for too long this is when mine blew
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate
Last edited by Robbgnarly at Dec 24, 2013,
#4
With capacitors sometimes you get lucky and can see visually. They typically have an expansion "cap" that is designed to vent pressure if they fail. Other times you can tap on them and hear it. I don't recommend tapping on them as the amp has to be live and there are lethal voltages present.

A good visual inspection is the first step. Look to see if the PCB is discolored and see if any of the caps blew their lids(the round electrolytic).

Did you check to see if the fuse blew again?
Quote by DeathByDestroyr
See, it's important that people clarify when they say "metal", because I pretty much always assume they are a Cannibal Corpse fanboi.
#5
^+1
there was a black/burnt spot on the PCB where the cap sat.

Are any of the tubes white in color at the top? The silver on them is normal, but white is not
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate
#6
Before you start to take apart your amp, connect a patch cord to your f/x send to the return, and make the f/x loop bypass contacts don't have corrosion.
#7
^+1 that is an easy test. You can also plug your guitar directly into the FX loop return. This bypasses the preamp, if you get sound it is the preamp that has problems and if not it is a problem in your power section.
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate
#8
Ok so ive ran it up with no tubes and the fuses did not blow. ive plugged directly into the return and got no sound. and after looking a little closer 2 of the tubes have white tops. i'm really hoping this turns out to be nothing but some bad tubes. i also think that the soldering on the standby switch might need to be redone, could be a possible short. what do you guys think?
#9
I would get a set of tubes and take it to a tech. There is something going on inside the amp that is not right. I know you want it to be a simple fix (I hope so for your sake) but I have a feeling your having the same overheating issue that was very common with the early versions of the DSL's.

Is it the power tubes that are white?

What type of tubes are in it? Mine had SED =C= EL34 which are great, but they run $180 for 4 tubes. The JJ E34L (not EL34), JJ 6Ca7 and JJ KT77 are great replacement tubes and they are way cheaper than the SED (I prefer the SED personally)

Good luck and Merry Christmas
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate
#10
Quote by Robbgnarly
I would get a set of tubes and take it to a tech. There is something going on inside the amp that is not right. I know you want it to be a simple fix (I hope so for your sake) but I have a feeling your having the same overheating issue that was very common with the early versions of the DSL's.

Is it the power tubes that are white?

What type of tubes are in it? Mine had SED =C= EL34 which are great, but they run $180 for 4 tubes. The JJ E34L (not EL34), JJ 6Ca7 and JJ KT77 are great replacement tubes and they are way cheaper than the SED (I prefer the SED personally)

Good luck and Merry Christmas



They are svetlana EL 34's. 2 of the preamps were the original marshall ECC 83's which are very white. thank you for the advice and im really hoping its not the overheating issue. merry christmas to you as well
#11
Quote by joejoe0909
They are svetlana EL 34's. 2 of the preamps were the original marshall ECC 83's which are very white. thank you for the advice and im really hoping its not the overheating issue. merry christmas to you as well

Do they have a =C= mark on them? SED was originally known as Svetlana Electron Devices but sold the name Svetlana to New Sensor 10 or so years ago. If they have an S lable they are the modern tubes by New Sensor not SED.

I did find that the new Mullard 12ax7 in V1 and V4 with a JJ Ecc83 in V2 and V3 will get a great tone out of the DSL.

What is your closest big City? May be someone knows of a good tech you can take it to.
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate
Last edited by Robbgnarly at Dec 24, 2013,
#12
If it is overheating the fix is pretty easy for a tech. You upgrade the bridge rectifier, to one with a heatsink preferably.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#13
2 are white? That's very rare- white means air is in the tube. Any chance they broke when you pulled the shields off of them?

Did the fuse blow with the tubes installed? And then not blow with them removed?
Quote by DeathByDestroyr
See, it's important that people clarify when they say "metal", because I pretty much always assume they are a Cannibal Corpse fanboi.
#14
Yeah, white is usually busted glass.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#15
Quote by R45VT
2 are white? That's very rare- white means air is in the tube. Any chance they broke when you pulled the shields off of them?

Did the fuse blow with the tubes installed? And then not blow with them removed?


they may have been damaged by me when i was troubleshooting and they don't have shields. the fuse blew one time, when i got it home and tried it out, i've replaced the fuse and it hasn't blown again (with or without tubes)
#16
Quote by Cathbard
If it is overheating the fix is pretty easy for a tech. You upgrade the bridge rectifier, to one with a heatsink preferably.



can you please post a link for the part you recommended?
#17
http://au.mouser.com/ProductDetail/Rectron/BR66/?qs=sGAEpiMZZMtQ8nqTKtFS%2fNgL6ac11fJur9L2GZlpAe8%3d

http://au.mouser.com/ProductDetail/Aavid-Thermalloy/530614B00000G/?qs=%2fha2pyFaduiVU%2fPHIqilq%2f7h7sbp8wZ21CeVlodF4%252bDe9G2558tsEw%3d%3d

They should do the trick. It is unlikely to be the problem though, the early 401 amps were the ones that had most trouble, not the 50s. Easy enough to know, if it is the problem you will see some scorching on the pcb beneath the rectifier.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band