MKIIB Lead Master -pull bright pot wiring? -1982 RP-9C circuit board (SRG) Serial # 8751

[edge59AlnicoIV]

Im no amp tech but why would someone wire up a pull switch just to connect two ground points? Are you absolutely sure that lug is ground? Put a continuity meter on it to be sure, with the pull bright switch pushed in. Put a lead on it and the other to chassis. On V3B, that fatter grey lead from pin 7, is that going to the middle lug of pot?

Look at the schematic I posted of the IIB

 

[edge59AlnicoIV]

Im no amp tech but why would someone wire up a pull switch just to connect two ground points? Are you absolutely sure that lug is ground? Put a continuity meter on it to be sure, with the pull bright switch pushed in. Put a lead on it and the other to chassis. On V3B, that fatter grey lead from pin 7, is that going to the middle lug of pot?

If in doubt, contact Mesa, they will ster you straight, I have done and said all I can think of believe me I have been in several of these amps, they change all the time, but your amp is a IIB, call Mesa and give them your serial #

 

[edge59AlnicoIV]

Look at the schematic I posted of the IIB

 

[edge59AlnicoIV]

If in doubt, contact Mesa, they will ster you straight, I have done and said all I can think of believe me I have been in several of these amps, they change all the time, but your amp is a IIB, call Mesa and give them your serial #

 

[Jamme1961]

yea its a ground - and yes the grey fat wire is going to middle lug of the pot. everything on the amp is working.

 

[Jamme1961]

This one looks like mine

 

[Henz]

This one looks like mine

I found this on a IIB thread. This is the way that I've seen pull brights function. But like you mentioned and Edge59, many variations out there.

 

[Jamme1961]

yea it looks lie my amp is stk I found a couple 9C boards wired the same way here's another one just like mine -

 

[Jamme1961]

it be nice to get pictures of all the different versions out there. here's a MKIIB 9A board similar to my 9C