Fender pro junior bad transformer and red plating v3 tube

[The Dude]

^^^^^^ What he said. What is the voltage at TP4 or the cathode of V1B?

[bluestom50]

Test point 4 is 1.8 vdc I just discovered that r33 is not in connection with either r3 or r18. I will check things out tomorrow when I am more alert. Ill let you guys know and thanks for all your help and encouragement Tom

[bluestom50]

I feel that all is in order with my components and tried different tubes. I still have no signal passing through this nightmare of mine. I feel the problem is in the pre amp section but am not skilled or smart enough to figure it out. I took reading off all tube pins with the hope that it might mean something to someone who can help me.. V1 PIN (1) 3VDC (2) 0 VOLTS (3) 3VDC (4) 3VAC (5) 3VAC (6) 209VDC (7) 0 VOLTS (8) 2VDC (9) 0 VOLTS ------------ V2 (1) 151VDC (2) 23VDC (3) 3VDC (4) 3VAC (5) 3VAC (6) 209VDC (7) 0 VOLTS (8) 2VDC (9) 3VAC ----------- V3 (1) O VOLTS (2) -13VDC (3) 0 VOLTS (4) 3VAC (5) 3VAC (6) 0 VOLTS (7) 324VDC (8) 0 VOLTS (9) 299VDC ------- V4 MEASURED IDENTICALLY TO V3 ANY HELP WILL BE APPRECIATED AS I AM LOST THANKS, TOM

[Enzo]

Your very first reading. Pin 1 of a 12AX7 is a plate. You have 3v, but it should be more like the other pins 1 and 6, 150vDC. My first suspect is R10 is open, a 100k. It would be very difficult for a tube there to short that pin to ground anyway, and since you already tried other tubes, that reinforces my theory. Oh, wait, I have a second idea. The socket for V1 is on the little socket board, and the connections to it come through that ribbon cable next to the socket, from the main board. If that ribbon has a broken connection, then you lose voltage. R10 is near the center of that row of seven resistors near the ribbon, find it on the parts layout diagram. See if there is 3v on the bottom end or more like 230v. If 3v like on pin 1, then the resistor likely open, or possible unsoldered, but if more like 230v, then the ribbon connection is probably bad.

[bluestom50]

Thanks to all of you for your help and encouragement I finally have the amp back in working order. R 10 had a bad connection plus I found a couple other questionable connections.Live and learn I guess. Thanks again and this is a real nice forum. Tom