1990 jcm 900 model 2100 problem "cuts out"

fredsalright · 06-23-2008, 12:59 AM

Hi

I bought a 1990 jcm 900 model 2100 recently. I assume the brown bottomed
El34 Marshall tubes are original as the preamp tubes. Problem is after 15 minutes of playing either the bottom end cuts in and out... and or the power drops low or all the way out. The channel switcher is also weird. The LED is real dim when engaged and also it works inconsistently. Any ideas would help much because I'm broke... But handy with a soldering iron. Thanks

DragonSarc · 06-23-2008, 01:23 AM

you might just have to replace your power tubes and it should work again.

5er driver · 06-23-2008, 01:55 AM

I had the same problem with my SL-X. Turns out that the input/output jacks get dirty and/or corroded sometimes. Some of them are switching jacks which adds another area for something to go wrong. The main culprit on mine was the effects loop return jack. What I did was douche all the jacks in the amp (front, back, and speaker outs too) with electronic contact cleaner/lube and ram a guitar cable plug in & out of them about 20 times. That solved my problem. I hope your problem is as simple as that. If it is, clean 'em periodically.

06-23-2008, 12:59 AM	#1 (permalink)
fredsalright Junior Member Join Date: Jun 2008 Posts: 1	1990 jcm 900 model 2100 problem "cuts out" Hi I bought a 1990 jcm 900 model 2100 recently. I assume the brown bottomed El34 Marshall tubes are original as the preamp tubes. Problem is after 15 minutes of playing either the bottom end cuts in and out... and or the power drops low or all the way out. The channel switcher is also weird. The LED is real dim when engaged and also it works inconsistently. Any ideas would help much because I'm broke... But handy with a soldering iron. Thanks

06-23-2008, 01:23 AM	#2 (permalink)
DragonSarc Senior Member Join Date: Jun 2008 Location: San Leandro, CA Posts: 275	Re: 1990 jcm 900 model 2100 problem "cuts out" you might just have to replace your power tubes and it should work again.

06-23-2008, 01:55 AM	#3 (permalink)
5er driver Member Join Date: Dec 2007 Location: Stuttgart, Germany Posts: 89	Re: 1990 jcm 900 model 2100 problem "cuts out" I had the same problem with my SL-X. Turns out that the input/output jacks get dirty and/or corroded sometimes. Some of them are switching jacks which adds another area for something to go wrong. The main culprit on mine was the effects loop return jack. What I did was douche all the jacks in the amp (front, back, and speaker outs too) with electronic contact cleaner/lube and ram a guitar cable plug in & out of them about 20 times. That solved my problem. I hope your problem is as simple as that. If it is, clean 'em periodically. __________________ The 5er Driver "Plug that beotch in an' let her rip!"

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