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Discussion Starter #1
Have an RCA 52929 ptk195 chassis. Convergence is off around the center perfect in the middle. Like a "fish eye"
effect. I have the convergence menu (not advanced convergence, just the first level). When green centering I have wavy lines on the outside, blue and red convergence work beautifully.

I have tested the power board for convergence voltage output with the following --- ground to the outside of the rf input, positive to the pins on the output side. I get no voltage whatsoever-- I have confirmed 120 on the input side at the connector.

I bought a used power supply from a reputable dealer who had tested the part before sending it and switched them out. Same thing with NO power on the outputs, but convergence menu is gone and there appears to be no convergence at all. How could this be? If they are outputting no voltage how could there be a difference? Perhaps a faulty ground?

Is there a way to check the power board disconnected from the chassis?

By the way I know this is a tough set to troubleshoot!
 

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What you are describing makes no sense to me. If you had no power to the output stage the red and blue would not work perfectly. If you have a problem only with green you need to troubleshoot the green part of the circuit.

I would be looking for coolant on the boards very carefully. Leaks are quite common.

Your problem with the other board may be that you missed some connection, that the board is not identical, or that the board is defective (very common).
 

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Discussion Starter #3
Thanks for your reply!

Doesnt make sense to me either.

I dont want to troubleshoot further until I can rule out the power supply, since all roads seem to lead in that direction. Checked thouroughly for leaks-- none there.

Here's what I would really like to know. Is my test of the output voltages flawed? If I have confirmed 120 on the hot side can I get a voltage reading by disconnecting the convergence voltage out connector, taking the ground to the rf connector and testing each pin on the power board (with the output connector removed) is this correct? Or do I need to take the readings at the convergence board itself? (where if so?) I need to discover where the board picks up the chassis ground--- and the schematics aren't helping. Until I am sure that I have power off of this board I am at a standstill.



If I had the board completely removed from the tv, applied 120 to the and referenced the voltage back to the transformer ground, would this be a correct method also to check voltages?

Thank for your time.
 

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You cannot test the board out of the set. You need to have it all together and the syscon needs to turn it on.
 
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