Rca 42PA30RQ No picture Multiple clicks

[1997eclipsegst]

Hi everyone,
Working on a Rca 42PA30RQ plasma for a friend. When he brought the tv to me it would click multiple times when trying to power up. Tested the Va and Vs on the power supply and it would go up to the proper voltage then quickly drop to zero. I then tested the Y-main and X-main. Found shorted components on both boards.

Y-main
Q5003 - RJP30E2
Q5007 - RJP30E2
Q5008 - RJP30E2

X-Main
Q4007 - RJH30E2
Q4001 - RJH30E2

I ordered replacenet boards off ebay and before installing them I checked to see if either board had any shorted components and they didn't. Installed the boards and powered it up, It had a couple of colored pixel lines on the screen then I heard a snap. I unplugged it and tested the boards and the Q4007 and Q4001 are shorted on the X-Main now. The Y-Main appears ok. Does this sound like a bad panel shorting the boards out?

[tom66]

Re: Rca 42PA30RQ No picture Multiple clicks

These Samsung panels are notorious for blowing the X-main, although it's due to software not hardware or panel failures. A panel can't kill the X-main as far as I am aware. Did you secure all of the screws on the boards?

[1997eclipsegst]

Re: Rca 42PA30RQ No picture Multiple clicks

Both boards were secured to the panel with screws. Do you think the replacement X-Main could have been defective to begin with? Any other checks I can do before ordering another board?

[tom66]

Re: Rca 42PA30RQ No picture Multiple clicks

On this set, you can run the TV without an X-main and get a dim, distorted image. That will usually rule out panel defects.

[1997eclipsegst]

Re: Rca 42PA30RQ No picture Multiple clicks

I unplugged the X-Main ribbon and power connector, turned on and nothing. Tested the VS and VA, they would go up to 207vdc on VS and 54vdc on VA then drop to zero. The logic board has a 5sec on and 2sec off flash pattern. I then disconnected the Y-Main ribbon and power, turned on and the VS reads 207vdc and 54vdc VA.It will stay at that voltage and doesn't drop. The logic board is flashing 1sec on 1sec off. I tested the Y-Main and doesn't have any shorted components on the heat sink like the other one I pulled out did. Does it appear that I have another bad Y-Main as well. The X-Main is for sure bad with Q4007 and Q4001 shorted. I found the link to your video on testing buffers so I tested the buffer and didn't find any shorted components.

[tom66]

Re: Rca 42PA30RQ No picture Multiple clicks

I believe Samsung may have altered the design on this to make the set shut down with a missing X-main -- not sure why.
I would try and replace the X-main, perhaps it was originally faulty.

[1997eclipsegst]

Re: Rca 42PA30RQ No picture Multiple clicks

Thanks for the reply Tom. Would there be any tests I can do on the replacement X-Main when I get it? The X-Main that is in the set now didn't have any shorted components until I tried to turn it on and it cooked the Q4007 and Q4001. The original X-Main that was in the set when brought to me had the same Q4007 and Q4001 shorted as well.

[tom66]

Re: Rca 42PA30RQ No picture Multiple clicks

Did you make sure the control board connector is hooked up properly? Check all of the FETs on the board for shorts and across Vsus and GND.

[1997eclipsegst]

Re: Rca 42PA30RQ No picture Multiple clicks

Yes I made sure that the ribbon was seated all the way in the connector. I will get a replacement on the way and see what happens. Thanks for your help.

[Bling23]

Re: Rca 42PA30RQ No picture Multiple clicks

I have the exact same problem with a tv I'm trying to repair. So replacing the y-main fixed the problem???

[1997eclipsegst]

Re: Rca 42PA30RQ No picture Multiple clicks

I actually worked on this tv yesterday and had it working. I have a working Insignia plasma that has the same internals as the RCA does. I swapped some parts from the Insignia to see if I could get it to run before ordering more parts. Swapped in the X-Main, tried to turn on and nothing. Swapped in the Y-Main, tried to turn on and nothing. With both of these parts installed I would get one click from the power supply, the VA and VS would read the correct panel voltage then drop to zero. I then swapped the Y-Buffer, and it came to life! I had previously tested the buffer and thought it tested good, but after checking it again I found 2 lines that were shorted. You might want to check your buffer as well.
Tom66 has a great video on testing buffers:
http://www.youtube.com/watch?v=51SZsfH60EY

[tom66]

Re: Rca 42PA30RQ No picture Multiple clicks

Glad to hear you fixed it.

[1997eclipsegst]

Re: Rca 42PA30RQ No picture Multiple clicks

Thanks Tom. I am glad I was able to get it working too.

[1997eclipsegst]

Re: Rca 42PA30RQ No picture Multiple clicks

I just wanted to update this. I received the replacement Buffer and X-Main. TV has been working great for the past 3 weeks. Thanks again to everyone on this great site.

One other thing I noticed on the replacement X-Main I received is this one has a SF10A400H Ultra Fast Recovery Diode in location C4019. The original that came out of the tv and the 1st replacement board did not have this. The new replacement has a newer date code then the other 2. Any thoughts that this may be a revised board since these X-Main's have so many problems?

[tom66]

Re: Rca 42PA30RQ No picture Multiple clicks

It's probably to provide extra protection to the main FETs.
Did you apply the software update to the TV? Is it even possible on an RCA plasma?

[1997eclipsegst]

Re: Rca 42PA30RQ No picture Multiple clicks

I checked for software updates for this but didn't have any luck.

[tom66]

Re: Rca 42PA30RQ No picture Multiple clicks

If it does fail again I would recommend replacing the control board with a newer revision.

[1997eclipsegst]

Re: Rca 42PA30RQ No picture Multiple clicks

Sounds good. Thanks for the recommendation.

[doc047]

Re: Rca 42PA30RQ No picture Multiple clicks

Same issue, same TV. I replaced the power supply to no avail. I replaced the Y buffer and Y main at the same time and that worked great. Just wanted to share, as I used this forum in my research.

[philliesfan30m]

Re: Rca 42PA30RQ No picture Multiple clicks

i know this is an old thread but i didn't feel the need to start a new 1 since i have the same issue the x and y main have shorted transistors and the y buffer has a few bad lines. i ordered all 3 but they haven't arrived yet. i have 2 questions on post 14 he states that the new x-main has a SF10A400H Ultra Fast Recovery Diode in location C4019. 1st question is if the board i get doesn't have that diode should i put 1 in that location because i have 1 that i can take off another board or should i just let it the way it is? i figure it might be needed if it was added to the newer revision and it can't hurt if i do put it in. 2nd question is the x-main taking out the y-main and buffer or is the buffer taking out the y-main and x-main if that is possible? i'm not real familiar with plasmas hopefully tom66 might be able to explain what might be going on.