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frsimen · 29th Oct 2021, 5:17 pm

PJL may well have spotted what is wrong in post 53.

A couple of additional tests would be worthwhile trying.

1) Switch the HORIZONTAL MODE switch to A and turn the A/B SWP SEP control to the mid position. Measure the voltage at the collectors of Q377 and Q387. You should be able to make them equal (9V approximately) by adjusting the Channel 1 shift control to somewhere near the mid position (assuming channel 1 has been selected).

2) If test 1 passes, try adjusting the A/B SWP SEP control. It should make no difference to the Q377/Q387 collector voltages when the A/ALT/B switch is in the A position.

If both tests pass, your oscilloscope is working correctly. If not, the fault finding will need to continue.

29th Oct 2021, 5:17 pm	#54
frsimen Heptode Join Date: Jan 2011 Location: Croydon, London, UK. Posts: 773	Re: Tek 2215. Vertical Amplifier Issues. PJL may well have spotted what is wrong in post 53. A couple of additional tests would be worthwhile trying. 1) Switch the HORIZONTAL MODE switch to A and turn the A/B SWP SEP control to the mid position. Measure the voltage at the collectors of Q377 and Q387. You should be able to make them equal (9V approximately) by adjusting the Channel 1 shift control to somewhere near the mid position (assuming channel 1 has been selected). 2) If test 1 passes, try adjusting the A/B SWP SEP control. It should make no difference to the Q377/Q387 collector voltages when the A/ALT/B switch is in the A position. If both tests pass, your oscilloscope is working correctly. If not, the fault finding will need to continue.