This guy has an RCA 42PA30RQ

[tom66]

Re: This guy has an RCA 42PA30RQ

I actually have the boards in front of me ripped out of a Wii victim

[Bling23]

Re: This guy has an RCA 42PA30RQ

over view shot for all the viewers

[Bling23]

Re: This guy has an RCA 42PA30RQ

Update with this plasma. I checked my Y-main and came across 4 out of 8 mosfets and Transistors shorted out. I ordered replacements and soldered them onto the Y main board and I have the same problem. As a plan B, I ordered a Y-main board to swap out. I'm praying this fixes the problem.

[Bling23]

Re: This guy has an RCA 42PA30RQ

Ok. So I replaced the Y-main and the Y buffer board today. With all the connectors in their appropriate places, I was still getting the multiple on and off from the power supply. Basically the problem had not changed. So I started my process of elimination by disconnecting the connectors for each board until I isolated the problem. Before the x-main and Y buffer board swap out, I was not getting any Va/Vs voltage at the PSU pin connectors. So, I disconnected the X-Main board first to see if I would get Va/Vs from the PSU with everything connected minus the X-Main...sure enough I am getting 207 Vs and 54 Va. Also now without the X-main connected, I don't get the multiple on and off from the power supply relays. So I'm going to try my hand at checking the X-main for any shorted components and try to repair the X-main. But as a back up..I ordered a replacement X-main board. Oh I connected my oscilloscope up to the new Y-main board as Tom66 explained and I'm getting Vmax =44.0V....Vmin =-60.0V Vrms=54.5V Vavg =54.4V Vpp= 12-16V

[Bling23]

Re: This guy has an RCA 42PA30RQ

Photo of the voltage readings from Oscilloscope

[tom66]

Re: This guy has an RCA 42PA30RQ

Definitely not working. You should be seeing a wave not a static DC voltage. I am aware that these boards will give out a DC voltage just after they are turned off. This may be your problem - a protection circuit tripping. Or the y-main is faulty.

[Bling23]

Re: This guy has an RCA 42PA30RQ

Now I'm confused...I replaced the y-main and Y-buffer and I'm getting correct vs and va without the relay switching on and off

[Bling23]

Re: This guy has an RCA 42PA30RQ

Does that mean I purchased a bad Y-main??

[Bling23]

Re: This guy has an RCA 42PA30RQ

I think it's a protection circuit tripping but how do I find out where or what it is? That's going to be a challenge

[tom66]

Re: This guy has an RCA 42PA30RQ

With X-main removed you should see some brief pulses on the Y-main output -- do you?

[Bling23]

Re: This guy has an RCA 42PA30RQ

Maybe I'm hooking up the oscilloscope wrong on the cap. I attached the probe to the topmost lead as its installed on the board. Confirm I'm to take the ground clip and attach it to ground on chassis ? Or don't connect to ground?

[tom66]

Re: This guy has an RCA 42PA30RQ

Scope should be grounded. Can you show me a pic of where you are attaching it to?

[Bling23]

Re: This guy has an RCA 42PA30RQ

sure can but can i was just probing around the primary side of the PSU and this is what I have on the two diodes

[Bling23]

Re: This guy has an RCA 42PA30RQ

also when i plug the tV power in, this is the wave from from the transrfomer on the Y-main before the second power of click happens and then it flat lines

[tom66]

Re: This guy has an RCA 42PA30RQ

Were you on 1X or 10X?

[Bling23]

Re: This guy has an RCA 42PA30RQ

i was on 10x

[tom66]

Re: This guy has an RCA 42PA30RQ

Were you probing on the primary or secondary?

[Bling23]

Re: This guy has an RCA 42PA30RQ

That wave from was by me just placing the tip of the probe on top of the transformer on the Y Main, and this how I set up the probe to to ground when checking the cap

[tom66]

Re: This guy has an RCA 42PA30RQ

That indicates the transformer's being driven, which more or less means that it's working. Please can you try the measurement for the capacitor on 500ms/div. Set the scope up so trace sweeps left to right (put horizontal position on the lefthand side.) Press STOP, plug TV in, then press RUN immediately after doing this, then once the trace nearly reaches the end, press STOP, and show me what it looks like. Note that the Rigol has a USB port, so you can upload the bitmaps it makes directly instead of taking a picture.

[Bling23]

Re: This guy has an RCA 42PA30RQ

ok..i'm setting it up..