need help with odd CRT monitor image

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well, i got the new chassis and its working correctly. turns out my chassi s i recapped and went all sorts of nuts on is most likely good. it was the control board with size, horz, vertical, contrast and the other adjustment s. it plugs in via a ribbon cable. if i use my old control board with the new chassis, i get the same half image. i never thought control board, as i got the half image with the board connected and unconnected, and mvoing t he pots made no difference. i have both boards and will go over the pots, r esistors, 1 diode and 1 cap. see whats bad on the affected board, maybe the cable itself. its soldered, not crimped. i cant really test my old chassi s, i had to use my old neck board, it was for a 13, not 19 inch monitor. n ot going to swap neck boards back and forth, im just glad its working. i wi ll let all know if i find the control board issue

Thanks for the update! I had forgotten about the sub-board controller too, and we have run into that with other monitors.

I suspect now that one of the vertical potentiometers is damaged.....

John :-#)#

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assis i recapped and went all sorts of nuts on is most likely good. it was the control board with size, horz, vertical, contrast and the other adjust ments. it plugs in via a ribbon cable. if i use my old control board with the new chassis, i get the same half image. i never thought control board, as i got the half image with the board connected and unconnected, and mvoi ng the pots made no difference. i have both boards and will go over the pot s, resistors, 1 diode and 1 cap. see whats bad on the affected board, maybe the cable itself. its soldered, not crimped. i cant really test my old ch assis, i had to use my old neck board, it was for a 13, not 19 inch monitor . not going to swap neck boards back and forth, im just glad its working. i will let all know if i find the control board issue

the vert pot is open. schematic shows a 500ohm B pot. what is the b for. tw o of the pots have the b suffix. google had conflicting info that its a lo g pot, but testing the good one with a dvm, it looks linear( i need a batte ry for my analog meter) . thanks

Cute, will try to remember damaged pots for the future. Always look for the simple stuff first - usually my rule, but hey, who expects broken pots?

And, of course, I should.

John :-#(#

Pots became extinct just before CRTs. Now all the settings are on EEPROM.

Another vertical pot problem I have seen is leakage between the potentiometer and a grounded case.

The one I've seen most of is loose rotor and flaky contact between wiper and track.