Motorola 17T21 Flyback & Schematic

[dieseljeep]

Originally Posted by Mre12ax7

I will be testing all the voltages on the horiz, output and osc tubes.
I will use my Fluke 87 DMM or my Eico VTVM with the set plugged into a isolation transformer.

Also, check the voltages on the audio output tube. It's used as a voltage divider, known as stacked B+. Try substituting the 25L6 tube.

[Mre12ax7]

The audio is working fine I hear static when the volume is turned up ( I made a mistake in my other post)
Voltage measurements: ( taken with Fluke 87, horiz, out plate cap off)
25L6
pin 8 159v Sams 150v
25BQ6
pin 4 136v Sams 135v
pin 5 -37v Sams -32
pin 8 0v Sams 0v (gnd)
6SN7
pin 1 -9 Sams -13 (varies with horiz, hold potentiometer could not get it any lower)
pin 2 182v Sams 135v
pin 5 197v Sams 175v
pin 6 6v Sams 6v
pin4 -.034v Sams -.3
Boost (measured at terminal 1 on flyback)
265v Sams 435v The plate cap is off of the output tube so that could affect that.

The plate voltage for the 6SN7 is way off. Is this related to the dropping resistor?

[Mre12ax7]

I have gotten the set to display a picture.
The only thing is that it will not lock on powerup, you have to adjust the horiz, hold.
It seems there is some component that will not allow the set to lock when cold until it warms up after about 2 minutes.