G07 problem.

jkoolpe

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Hey all!

I have a malfunctioning G07 on my hands (from a Defender). I capped the monitor, and it worked for about 10 minutes before something else quit on the deflection board. At first, I had no B+ voltage at all, and no HV (totally dead). It was not the chassis fuses.

I replaced the large B+ filter cap and the B+ voltage is now back along with HV, but the B+ is too high (reading 160 V on one side, 170 V on the other side of the large, white ceramic chassis resistor (R1)). I have no neck glow, and of course no picture. I tried adjusting the B+ pot, but the voltages did not change at all.

I then tried taking out X701 (as per the G07 flowchart) and the monitor then appeared to work (neck glow returned, and I saw a diffuse blob in the center of the screen). I then tried a new voltage regulator (1106), but no change.

I've tested the 4 power diodes (900 series), and they appear to be good and also all of the resistors in the area. Even replaced cap C511.

Still no good. Any other ideas why my B+ voltage continues to be too high?

Jon
 
check over ALL the 900 parts for cold solder - especially all the big parts. Wiggle them while watching the solder. And did you replace R908?
 
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