Have a pentranic monitor, the monitor worked in the shop... pushed it on the truck...drive to location 30 mins away...dead. (of course) Drag it back to the shop and find plenty of B+ but no switching of the HOT or flyback. search for broken traces but find none.
Traced to failed resistor R331 that feeds power into the HA11235 IC chip. replaced chip and resistor.
Monitor powers on, but now raster is whiting out the screen. can faintly see video. Brightness control does nothing. Screen control on flyback is still factory sealed so it hasn't been changed. checked the brightness pot...wiring... replaced switching transistor (Q108) and checked all the diodes and resistors in the area... all check out good. replaced neckboard with known good, same thing. Issue is deflection board.
B+ is 108v (within spec). "18v" is a little low at 15.8v but not so low as to consider it an issue.
At a Loss where to look from here.