About half a year ago the screen began to blink after powering on the CRT. It started to blink with thin horizontal line placed randomly approximately once a second. After 5 minutes it blinked with wide horizontal blocks. And after 10 minutes the whole screen blinked. Then the picture became stable. I noticed that if the signal contained a lot of white color, the time of blinking reduced.
Several days ago the monitor was taking up a lot more time to get stable (several hours) and finally it stopped showing non-blinking picture. It just rarely blinks.
I tried to rotate F1, F2 knobs of the FBT clockwise and counterclockwise with no results.
I replaced transistor Q912 (2SA1273) as it was recommended here http://www.fixya.com/support/t118996-green_amber_amber_code
), but with the same one. I also replaced pre-amplifier IC302 (LM1267NA). After this operations the monitor's behavior kept the same.
I measured some voltages, which floated synchronously with the blinking. They are: RGB inputs of pre-amplifier, VFBP, HFBP, HFBP1, G1(from -50 to -140) and Clamp. (I tested the signal cable's RGB signal and it was ok, the voltage became to float exactly on the pre-amplifier.) What this fact can tell us? Can broken flyback cause this effect?
May be it is a power failure? I checked 80V, 12V, 5V and they are fine. I measured them on the circuit that contains pre-amplifier, amplifier, because it's placed vertically, but I can't imagine how to measure the main board, that is on the bottom. So I have not measured 15V, 192V, 6.3V etc.