AMS--Soldering 101 class--the swamp deepens........

[Amp Mad Scientist]

M R not ducks
O S A R....C D E D B D wings???

ROFLcopter back atcha

Well I'll be. MR Ducs !

 

[eSGEe]

YOu can be if ya wanna BEE

 

[mcblink]

JCM2-64-02-01-S

So after a little bit of searching around the net, I'm frequently reading that this part has been discontinued.

It's looking like I might just have to solder a couple new pots onto the old pcb anyway....I think I can do it, but should I screw up royally (and that's always a possibility) I might be up poop creek lol

 

[Amp Mad Scientist]

So after a little bit of searching around the net, I'm frequently reading that this part has been discontinued.

It's looking like I might just have to solder a couple new pots onto the old pcb anyway....I think I can do it, but should I screw up royally (and that's always a possibility) I might be up creek lol

You can send the board and the 2 pots, and I will do it for you in 1 day.
Anything for our forum bros anytime. No problem.

 

[eSGEe]

now thats damn neighborly of ya AMS

 

[Amp Mad Scientist]

now thats damn neighborly of ya AMS

Any of our forum brothers or sisters.

 

[mcblink]

You can send the board and the 2 pots, and I will do it for you in 1 day.
Anything for our forum bros anytime. No problem.

Damn AMS, that's mighty fine of you. I'll get at ya when I get everything together. A million thanks!

 

[Inspector #20]

JCM2-64-02-01-S

JENNY-867-5309

 

[Amp Mad Scientist]

Damn AMS, that's mighty fine of you. I'll get at ya when I get everything together. A million thanks!

Yup you need 2X POTTR22K .
Those pots go bad a lot. I would definitely recommend changing those.

Marshall Amp Parts - DSL100

Marshall Amp Parts - Marshall Jacks

www.amprepairparts.com

About 60% of the amps that were having problems -it was the pots.
The other 40% was a bad power amp circuit board (the bias stability problem).

 

[mcblink]

So the pots are coming
A new quad of mullards are coming
Bias board has been removed


....and then I see R6 on the main board has exploded lol

This ought to be fun. There doesn't appear to be any actual burning on the board but now I get to remove the whole thing for closer inspection/cleaning/repair. I was hoping to avoid doing that again. But, by now I'm getting pretty good at it so it shouldn't take too long.

 

[mcblink]

@Amp Mad Scientist

Correct me if I'm wrong please....
R6 is a 1 ohm resistor in the bias circuit, correct? I have the schematic but it's dated 1997, so needless to say that I don't exactly trust it...

 

[mcblink]

 

[Mitch Pearrow SJMP]

Good luck Mike !!
I am no help at all here buddy