Welcome to Solid State Guitar Amp Forum | DIY Guitar Amplifiers. Please login or sign up.

June 19, 2024, 03:40:53 PM

Login with username, password and session length

Recent Posts

 

Marshall VS100R transistors

Started by markorock37, March 01, 2024, 12:34:07 AM

Previous topic - Next topic

markorock37

T3 pin 1 goes to C4
T3 pin 3 goes to R7
So that checks out as well. It would sure be handy if Marshall gave us some voltages and a board layout.

g1

Ok, the amp wants CBE then, so the parts are correct type.  If that is true then voltages for T5 in post #42 are impossible. 
The highest voltage for T5 should be at the emitter.
If it's easier for you to call them out as pin 1,2, and 3, that will work as well.
Recheck T5,T4, T6.

markorock37

Finally had a chance to get back to it.
T4 Pin 1 -37.3v
       2 +33.9v
       3 -37.8v
T5 Pin 1 +0.6v
       2 +36.2v
       3 +28.6v
T6 Pin 1 +33.9v
       2 +34.1v
       3 +33.7v
Amp is still on dim bulb tester

g1

T4 collector connects to T6 emitter, so not sure why you are showing different voltages for those pins. (T4 and T6 are BCE pinout)

markorock37


g1

From the voltages you listed, it would seem that T4 collector is connected to T6 base, as you have the same voltage listed for them.
But T4 collector should go to T6 emitter, so once again the voltages listed are questionable.