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During pre-show testing the monitor failed with no picture, HV or neck glow. The monitor chassis was removed for repair.
On the bench there was a faint click on power on, but otherwise no signs of life. IC2 (TDA2593) pin 1 supply measured 4.64VDC and pin 2 supply measured 4.74VDC. The bootstrap voltage for the horizontal oscillator IC was a bit low compared with the datasheet. With IC2 removed the supply voltage at pin 2 measured 11.1V. Replacing IC2 had no effect. Using a light bulb load, B+ measured 112.9VDC, slightly low versus 126VDC, but close enough. Suspecting something clamping the supply voltage, R107 was opened to disable the HV overvoltage shutdown circuit but there was no change. Bending out pin 3, horizontal drive, also had no effect. D15 (1N4004) checked out OK and R94 measured 9.99KOhm OK. The voltage drop across R45 was 2mV and across R44 was 170mV, no significant drop in either case and I suspected that the low bootstrap voltage may be by design.
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Despite the low boot strap voltage, IC2 pin 3 LOPT oscillator was running. The LOPT drive transistor TR17 base had no signal, however. I suspected TH2 line drive transformer was bad and one side tested open circuit. Replacing TH2 with one reclaimed from a spare chassis fixed this chassis, and it ran OK on the bench for several hours.