RCA projection TV Problem

Apr 21, 2008 6 Replies
E

My RCA rear projection TV has worked well after help from you TV service people in January, 2005. It has a chassis number of PTK195AC and is model P60812BL



At that time I found that the surface of the PC boards had some of the coolent and other debris which I cleaned and that fixed the problem.



Coming home from vacation today, the main fuse from the AC input failed. Upon replacing it, the convergence is all messed up. I went into the service mode using the front panel as the service manual describes, I can't seem to get the grid pattern that I got back in



2005. Can anyone tell me


  1. What typically goes wrong when the main fuse blows and the picture goes out of adjustment

  2. How do you get into the built-in geometric alignment grid pattern?

I am into the service mode, but it does not seem to have any pattern except the P:(for parameter) and V (for parameter value): on the screen.



I would like to nurse this TV along for a while. It has given good service and I have no reason to replace it other than the present problem. I really don't want to get into it deeply. For example, I would prefer NOT to get a chipper checker or have to hook an oscilloscope to it.



sci.electronics.repair


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E

Here is a photo of what the convergence problem looks like

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E

Here is a photo of the problem

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L

time for some new convergence amps and resistors

Here is a photo of the problem

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A

Time to actually get out the service manual and find out what particular voltage to the convergence circuit you have lost, and what caused that failure.

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E

OK...

I checked the voltages out of J19701 connector from the power supply to the convergence board. They are not to specification (at all).

pin 1 should be -45, is -1.8 pin 2 should be -15, is -1.9 pin 3 gnd pin 4 should be +23, is +23.3 pin 5 should be +15, is 0 pin 6 should be -45, is 1.7

If the plug is pulled going to P19304, all the voltages go to 0 volts at J19701 on the power supply board. The service manual says to "disconnect power supply". I took that to mean pull J19701. I assume that the power board is bad. My question is.. Was the board blown by the load of something wrong on the convergence board, or just a bad component. I checked the input diode bridge and it seems to be OK. I would guess I should replace the power supply board. I wonder how much that is? I would hate to blow it after changing it out. What are the chances of that?

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