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Hoffman Amps Forum image Author Topic: Can a 4-Lug Marshall Jack be Fixed?  (Read 1830 times)

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Offline jjasilli

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Can a 4-Lug Marshall Jack be Fixed?
« on: May 22, 2014, 05:28:49 pm »
Finally traced a vexing windy-crackling noise issue to a 4-Lug Marshall style Jack. (It's the FX loop return Jack in a VHT Special Ultra 6).  There'as a bad connection inside the Jack.  Noise goes away with a phono plug inserted.  Spritzing & cleaning didn't work.


Any suggestions to repair the Jack in place?  I know a replacement is cheap, but due to a complex layout, it's a major PIA to replace.

Offline sluckey

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Re: Can a 4-Lug Marshall Jack be Fixed?
« Reply #1 on: May 22, 2014, 05:45:58 pm »
Can you get a burnishing tool or strip of 220 sandpaper between the switch contacts?
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

Offline Jack1962

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Re: Can a 4-Lug Marshall Jack be Fixed?
« Reply #2 on: May 23, 2014, 07:53:30 am »
you can try what sluckey suggest, however , if it was sitting on my bench , to avoid future problems with this jack(which you will have) I would replace it.
Any tube unit can be brought back to life.
I never meet a tube I didn't like.

Offline jjasilli

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Re: Can a 4-Lug Marshall Jack be Fixed?
« Reply #3 on: May 23, 2014, 09:21:50 am »
Thanks guys!  Looks like I have no choice bu to replace it.  Sluckey's idea is brilliant in its simplicity.  I wrapped fine sandpaper around a section of 1/8" wooden dowel, held with double-sided tape. If it were a dirt/corrosion issue I'm sure this would have fixed it.  But there must be an incurable mechanical failure inside the jack.

 


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