27" K7500 low B+ voltage

QbertWPC

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I have a K7500 that displays an image for a few minutes, then the picture goes out, but high voltage remains. The B+ voltage drops to around 12v. After unplugging power, the B+ voltage climbs back up to around 48v before bleeding off.

The chassis has been recapped and has a new flyback. It worked fine for several weeks for 12hrs/day after servicing.

Any ideas/anyone willing to work on this chassis that can have it done in a few days?
 
Was this one I worked on?

I seem to recall working on one of the 74/75/20/50 models that had this happen, and the issue was a bad trace on one of the big caps, but I'm not positive...
 
Was this one I worked on?

I seem to recall working on one of the 74/75/20/50 models that had this happen, and the issue was a bad trace on one of the big caps, but I'm not positive...

No, the only chassis you've worked on for me was a 6100.

I know I still have high voltage because a neon lamp glows when held near the flyback. I don't have proper equipment to measure the voltage at the anode cap when on, so take that into consideration.
 
No, the only chassis you've worked on for me was a 6100.

I know I still have high voltage because a neon lamp glows when held near the flyback. I don't have proper equipment to measure the voltage at the anode cap when on, so take that into consideration.

What ground are you using on the chassis?
to measure the B+
Your dc voltage is to low to get HV.

have you found and any video B+ it comes from the fly
so if the fly is working then you would have voltages that
come from it like video B+
That voltage goes to the neck board for the rgb.pins
did you turn the screen pot up to see a raster..
Do you see filament glow?
Find the correct ground and measure the test point again..
like the vertical ic heatsink.
tip don't forget wells has a tS guide,schematics and voltages test point.
you just have to look for them..at the site.
 
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