93 SLP "Normal" channel not working

K

kurtsstuff2003

Active member
Just got a marshall slp reissue and the high treble or channel one seems to work fine but the "normal" or channel 2 does not? I've tried everything I can think of to sort it but to no avail. Yes..I've swapped tubes,chopsticked, jiggled, punched (kidding) etc...any other ideas??
 
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Yeah sounds like a bad input jack on the normal channel or the wiring is wonky somehow or is grounding out the input signal to ground somehow or the jack wiring to the 68K input mixer resistors are going to ground.
 
Channel 2 bypasses a gain stage. If channel 1 works then the jacks are fine as the signal passes through the jacks for channel 2 when using channel 1 when unjumpered.

Does the Jack wiring look reworked? It’s old enough that someone might have modded it and returned it to stock but didn’t know how to wire back channel 1 and 2 correctly OEM
 
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Only thing that's been done that I can tell is 5881-EL34 conversion via bias range resistor being swapped. The input jacks look to be untouched and I did pull them and all seems well. Probably beyond me and will need a tech with the right know how...lol!
 
Even if a solder connection looks good they can still be a cold solder joint especially with lead free solder. I'm not sure if they had gone to ROHOS compliant solder in 1993 yet.

You might also want to check to see if the Normal channel 1 Meg volume pot is bad and shorting to ground from the wiper.
 
harddriver said:
Even if a solder connection looks good they can still be a cold solder joint especially with lead free solder. I'm not sure if they had gone to ROHOS compliant solder in 1993 yet.

You might also want to check to see if the Normal channel 1 Meg volume pot is bad and shorting to ground from the wiper.
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I have the feeling that's the case ..The pot
 
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