10-02-2017, 05:53 PM
The voltages look right (within typical errors), so your problem is not in the main power supply.
Suspect that U940 is questionable. Looking at the CRT Circuit and Calibrator (schematic 11) it says that the focus and intensity pots are ganged. Each of these connects to half of U940 (intensity to U940A and focus to U940B). So a duff U940 would explain a dim, unfocused trace that does not respond to focus/brightness.
U940 is a Tek custom chip 155-0051-00, alas
But you need to look at the signals shown to the left of the schematic to be sure what is wrong.
Suspect that U940 is questionable. Looking at the CRT Circuit and Calibrator (schematic 11) it says that the focus and intensity pots are ganged. Each of these connects to half of U940 (intensity to U940A and focus to U940B). So a duff U940 would explain a dim, unfocused trace that does not respond to focus/brightness.
U940 is a Tek custom chip 155-0051-00, alas
But you need to look at the signals shown to the left of the schematic to be sure what is wrong.
