Help figuring out problem with Toshiba PB6643-2 monitor

Dion

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I have 2 monitors with same symptoms, flyback looks not working, but HOT is presumably ok, since it is not shorted. I have checked the power supply section, all voltages out are all availables.

before HOT, there is somekind of transformer driving it. I checked for ac voltage both sides. Primary side checked around 6v. Secondary side around 0.6v, i presumed it is not enough to drive the HOT. I check the circuit around the primary, nothing suspicious. I traced back the signal to the IC LA7850. For the horizontal drive, there is horizontal power on the chip pin, which i measured are a bit out of spec( from datasheet i read it should be 12v), measured around 10v. Problem is, not sure this is correct voltage or not. and have tried to traced where the voltage comes from, but no luck. I dont get where this voltage derived from.

Any help apreciated, thanks in advance.
 
Update: i found that the 12v line comes from AN7812 @QF04. The input voltage is just wrong, it dropped around 11volts. I guess i will have to check the power circuitry again. So far replacing the feedback opto have no effect.
 
hi have the same problem but also where is point to mesur B+ i can t find it let s me know
stay tuned
 
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