Stupid Question 47: What's the High Voltage reading on a 25" K7000

Black Matrix

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Stupid Question 47: What's the High Voltage reading on a 25" K7000

I have this K7000 that I'm working on. Its going into HV Shutdown......I think. I believe the HOT and Voltage Regulator are fine. Couldn't test a short between any of the pins on either. The monitor comes on and looks great....for about 20 minutes. Then HV shutdown... When it cools down it will come back on.

When I tested the HV with my HV probe it was reading 23K. Which seemed like it might be too High. Anyone know what it is supposed to be.

B+ is testing at 130 at power up, but I believe it creeps up as it gets warm. I turned it off the second time cause I was a little worried about X-rays.

Any ideas would be welcomed.

This monitor was supposed to have been recapped, with a new fly and I think a new HOT and VR regulator from the looks of it. Looks like whoever worked on it before did a pretty good job. But the flyback must have been a dud because it developed a short and was arking HV. I've since replaced the fly, and none of the usually culprits test bad.

Kind of stumped. Any suggestions.
 
Last edited:
sounds like you need to lay your hands on a flowchart
that would be a big help to you

try google images

good luck
 
I have this K7000 that I'm working on. Its going into HV Shutdown......I think. I believe the HOT and Voltage Regulator are fine. Couldn't test a short between any of the pins on either. The monitor comes on and looks great....for about 20 minutes. Then HV shutdown... When it cools down it will come back on.

When I tested the HV with my HV probe it was reading 23K. Which seemed like it might be too High. Anyone know what it is supposed to be.

B+ is testing at 130 at power up, but I believe it creeps up as it gets warm. I turned it off the second time cause I was a little worried about X-rays.

Any ideas would be welcomed.

This monitor was supposed to have been recapped, with a new fly and I think a new HOT and VR regulator from the looks of it. Looks like whoever worked on it before did a pretty good job. But the flyback must have been a dud because it developed a short and was arking HV. I've since replaced the fly, and none of the usually culprits test bad.

Kind of stumped. Any suggestions.

I think 23-25k is normal. Chad would know better though.

if you're getting 130V ever, the voltage regulator is good, and of course if you have high voltage at all, the HOT is good. scope out the resistors from the VR side to about the vertical IC, especially the bigger ones. they get hot and it weakens the solder joints. I would imagine you have a heating/cooling issue with the solder joints if the B+ is climbing the longer you leave it on. R101, R89, (whatever the other ceramic is), and R103 are the ones to really focus on. R101 and R89 in particular carry a lot of juice, they get super hot, and they will often have lifting solder pads. do the wiggle test on these, if you see some flopping on the solder side or the legs moving, you'll need to tighten that up. often you'll have no choice but to bridge the resistors to the next points in the circuit.

probably not your problem but I've had K7000s in the past with intermittent shutdowns that were caused specifically by a dirty shutdown pot; I still think the solder is your issue somewhere.

good luck
 
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