Jcm-800 4210

jgwalker · 10-18-2009, 06:07 AM

Hi Everyone,

Everytime I move the input jack on the amplifier the sound dwindles down to a thin tone which is about half the sound I usually get.

This problem happens on both channels and with/without effects loop inputs.

Furthermore, moving that jack back and forth I will usually get "Full Volume" from the amp (usually by pulling up a bit on the inputted instrument cord) but it is usually very temporary.

Do I have a simple input jack problem?

I've read here that power tubes can cause a similiar problem.

Procter2812 · 10-18-2009, 08:50 AM

Have you tried a different guitar cable?

jgwalker · 10-18-2009, 04:25 PM

Yes, I've got several different cables here that I've tested the input jack and all exhibit the same results.

LesBalls · 10-18-2009, 04:35 PM

If you are moving the instrument cable around and the amp is coming back to life and then dying down again, I would guess the input jack is the culprit.

steelhorse · 10-18-2009, 04:39 PM

May be the input jack itself that's messed up somehow. You may need to pull the chassis out and have a look.

jgwalker · 10-18-2009, 04:43 PM

Yeah....that seems to be the logical place to start troubleshooting. I think these jacks are soldered onto the circuit board so getting a clear look at it might be somewhat difficult but I'll see what I can see.

Wilder Amplification · 10-18-2009, 04:49 PM

If the input jack is mounted to the printed circuit board inside the amp, it very well could be that the solder joints on the board itself are broken (very common problem) and need to be re-flowed. If you know how to solder, this is a pretty easy task...but removing the circuit board can be a bitch.

10-18-2009, 06:07 AM	#1 (permalink)
jgwalker Junior Member Join Date: Oct 2009 Location: Arizona Posts: 3	Jcm-800 4210 Hi Everyone, Everytime I move the input jack on the amplifier the sound dwindles down to a thin tone which is about half the sound I usually get. This problem happens on both channels and with/without effects loop inputs. Furthermore, moving that jack back and forth I will usually get "Full Volume" from the amp (usually by pulling up a bit on the inputted instrument cord) but it is usually very temporary. Do I have a simple input jack problem? I've read here that power tubes can cause a similiar problem.

10-18-2009, 08:50 AM	#2 (permalink)
Procter2812 Senior Member Join Date: Mar 2009 Posts: 333	Re: Jcm-800 4210 Have you tried a different guitar cable? __________________ www.sexpistolstribute.co.uk JCM800 2203X JCM2000 TSL100 Marshall 1936 Gibson Les Paul Custom Orville Les Paul Custom Fender Highway One Stratocaster Boss EQ Ibanez Tube Screamer Crybaby Wah Boss TU-2

10-18-2009, 04:25 PM	#3 (permalink)
jgwalker Junior Member Join Date: Oct 2009 Location: Arizona Posts: 3	Re: Jcm-800 4210 Yes, I've got several different cables here that I've tested the input jack and all exhibit the same results.

10-18-2009, 04:35 PM	#4 (permalink)
LesBalls Member Join Date: Dec 2008 Location: USA Posts: 63	Re: Jcm-800 4210 If you are moving the instrument cable around and the amp is coming back to life and then dying down again, I would guess the input jack is the culprit.

10-18-2009, 04:39 PM	#5 (permalink)
steelhorse Senior Member Join Date: May 2008 Posts: 3,888	Re: Jcm-800 4210 May be the input jack itself that's messed up somehow. You may need to pull the chassis out and have a look. __________________ www.ricojronline.com 760-956-6619 Garmopat Pedal Mods "I wouldn't mind hearing your head smash through a glass door. That would be cool..." luekmeyer

10-18-2009, 04:43 PM	#6 (permalink)
jgwalker Junior Member Join Date: Oct 2009 Location: Arizona Posts: 3	Re: Jcm-800 4210 Yeah....that seems to be the logical place to start troubleshooting. I think these jacks are soldered onto the circuit board so getting a clear look at it might be somewhat difficult but I'll see what I can see.

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