RCA 42PA30RQ plasma tv problem

[Stude]

I have been reading all the threads here pertaining to this model tv, and have done some probing in the tv. Basically I would like you opinions to verify which boards I may need to repair this. I have ordered a Panasonic to replace it but would like to fix this set since the parts seem to be relatively inexpensive.

It was working fine until one evening my wife turned it on by the manual button and she said the screen lit for a moment and went blank. To my knowledge, there was no sound either, but I can't verify the sound because I am not sure what input it is on since the screen doesn't work.

The red LED is on, and will turn blue by either using the manual button or by remote. It clicks once (which is normal), and after a couple seconds will click again twice, and nothing happens.

I printed off one of the threads here which explains the boards and general locations, and explains how to check the boards by unplugging them one at a time. I also checked the Y buffer as is shown in the youtube video within the thread.

The results are as follows:
-Unplugged z-sustain only= still clicks 3 times when turned on
-Unplugged y-sustain AND z-sustain= clicks 1 time when turned on (normal)
-Unplugged y-sustain only= clicks 1 time when turned on (normal)
-Disconnected y-buffer from y-sustain only= still clicks 3 times when turned on
-I checked the voltage with y-sustain unplgged and have 205+- (va) and 54+-(vs)
-Tested y-buffer and found no continuity (shorts)

Since I can't weld new compnents on a circuit board with my MIG welder, and my soldering skills leave a lot to be desired, I am relegated to replacing complete board assemblies.
With the above info, I would suspect at minimum, it needs a y-sustain board.
So I am looking for your expertise on:
1) Is there anything else I should check before buying new boards?
2) What do you recommend I should get for boards?
I would rather err on the safe side than to install a board and burn it out again.

Thanks,
stude

[Stude]

Re: RCA 42PA30RQ plasma tv problem

After looking at shopjimmy.com, I noticed that one main board requires a firmware update.
-How do I go about that?
-Where does one get the updated "firmware"?
-Does this really stop failures as they are suggesting?

[Stude]

Re: RCA 42PA30RQ plasma tv problem

After looking at shopjimmy.com, I noticed that one main board requires a firmware update.
-How do I go about that?
-Where does one get the updated "firmware"?
-Does this really stop failures as they are suggesting?

Ok, so I might have found out how to go about downloading the info and installing in the tv. Would I be correct in assuming that I would install the firmware from Samsung on my RCA TV? Most of the boards are Samsung, so I assume that the complete tv is a rebadged Samsung... or is it not?

[tw2005]

Re: RCA 42PA30RQ plasma tv problem

The mainboard is not Samsung so I very much doubt you could upgrade the firmware on it following that guide.

Could look here, not sure if it will help at all.

RCA

I had the Samsung model with these boards, lasted 1200hrs and replaced the X,Y and buffers ( buffers were ok)

[Stude]

Re: RCA 42PA30RQ plasma tv problem

The mainboard is not Samsung so I very much doubt you could upgrade the firmware on it following that guide.

Could look here, not sure if it will help at all.

RCA

I had the Samsung model with these boards, lasted 1200hrs and replaced the X,Y and buffers ( buffers were ok)

I looked on the RCA website and they have nothing for my model that I found.
So, it appears that I should try to find the exact RCA replacements rather than an updated Samsung board that requires a firmaware update?
I wouldn't want repeated failures... especially since the original only lasted 18 months or so.

[Stude]

Re: RCA 42PA30RQ plasma tv problem

Well, I have replaced the x main, y main and y buffer boards, and although it only clicks on once, stll has no picture.
Any suggestions?

[freakaftr8]

Re: RCA 42PA30RQ plasma tv problem

Are you geting proper voltages to these boards still? Where did you purchase the buffer boards? If from a cracked panel tv I more than sure one or both buffer boards are bad that you purchased. If.so your old buffer boards may be ok if it was just a y sustain failure. Check new buffer boards for shorts.

[Stude]

Re: RCA 42PA30RQ plasma tv problem

Voltages are as follows...
PS connector to Y main:
VA- 55, then slowly to 0
VS- 206, then slowly to 0
15V- 15 steady
Connector Y main to X main:
VS-206, then slowly to 0
VE- 99, steady
VDD- 5 steady
Boards came from Retech tv in TN.
This has a single y buffer, as opposed to an upper and lower. I switched back to the original Y buffer board and no difference.
I tested the replacement Y buffer, per the video linked on this forum somewhere, and it tested ok, same as the original.

[capkid]

Re: RCA 42PA30RQ plasma tv problem

I'd pull your Y-main and X-main and check a few components on the heat sinks for shorts: https://www.badcaps.net/forum/showth...t=ns-50p650a11

[Stude]

Re: RCA 42PA30RQ plasma tv problem

I performed the test as instructed by the above linked thread. I found several bad diodes and transistors on both original boards. I checked my replacement boards and the X main tests ok, but there are a couple transistors on the Y main that show continuity, like 1-1.5 ohms.
So looks like I need another Y main, eh?

[tom66]

Re: RCA 42PA30RQ plasma tv problem

I would always advise both the X- and Y-main to be replaced simultaneously on these models, as replacing just one may lead to a "wounded" board damaging the other.

[Stude]

Re: RCA 42PA30RQ plasma tv problem

I found some further testing info for diodes and transistors on youtube, so I need to maybe clarify what I am seeing. I am testing with my meter in diode test mode.
I am familiar with diodes as there are several applications of such in the primarily mechanical field in which I have worked. Basically, continuity one way, not the other with an ohm meter.
Transistors, not so much... as I understand it, the transisitor would be basically a double diode, with a common leg?
With that said, my old Y main and my old X main showed shorted diodes with continuity both ways, and some transistor readings of 0.000 (shorted) as discussed in your link above.
Here is where the clarity is needed. When testing the replacement X main, I do not have any readings that show 0.000 between any of the legs of the transistors, and the diode tests ok (OL one way, 3.8XX the other). However, each transistor is not necessarily the same readings as one another.
On the X Main, there are 3 transistors with a center protruding leg, and 2 with straight legs. The readings on them are not consistent, not only in regards to ohms readings, but in regards to continuity. The first one tested using the center protruding leg as common, had one way each OL, one way each with a reading of .396, and .921, and then .631, between the outside legs one way, .561 the other. The next one with a center protruding leg reads OL-OL, and OL-.387 using the center leg as common, and from outside legs, .567 one way, OL the other.
Bottom line is I have no 0.000 readings on the replacement X main. But I am confused and concerned about the inconsistent readings on the transistors, even on transistors with the same part number. Maybe it is caused by the components being in the board, and therefore attached to other circuits and components?
I do have some diodes and transistors on the replacement Y main that read. 0.000, so I assume it is bad. I just want to be sure that the X Main seems ok before I request another replacement Y Main.

[Stude]

Re: RCA 42PA30RQ plasma tv problem

I would always advise both the X- and Y-main to be replaced simultaneously on these models, as replacing just one may lead to a "wounded" board damaging the other.

So regardless of tests, I should request all 3 boards again? Y Main, Y buffer and X Main...

[tom66]

Re: RCA 42PA30RQ plasma tv problem

You can leave the Y-buffer. Only replace X- and Y-main.

[capkid]

Re: RCA 42PA30RQ plasma tv problem

I personally don't trust the old Y-buffers and the tests performed to verify their states in these thin-profile Samsungs, but they rarely fail. Also, I'd perform the same heat sink component tests on your replacement X-main and Y-main before installing them.

[tom66]

Re: RCA 42PA30RQ plasma tv problem

Especially given a good number of the Y-buffers are damaged after the screen cracks (which they are pulls from, cracked screen sets.)

[Stude]

Re: RCA 42PA30RQ plasma tv problem

I was finally able to contact Retech Tv and explained the situation, and they are sending another Y Main and Y buffer. I metioned replacing all 3 boards to be safe, but I guess it is their call as the X Main tested maybe ok.
The guy metioned that the panels can short out even though there may not be any visible cracks, although he stated it is on seldom occasion that they see a bad one.
So, I will see what happens, and let you know how it ends up. Hopefully good, because if it doesn't work this time, it is probably headed to the transfer station to get recycled. "Gotta know when to hold em, and when to fold em".

[capkid]

Re: RCA 42PA30RQ plasma tv problem

I agree that the panels rarely are at fault in these Samsungs.

[Stude]

Re: RCA 42PA30RQ plasma tv problem

Update:
Received second Y main and Y buffer from Retech and installed. Checked the transistors and diodes on the Y main before installing. No shorts found. X Main had been checked, no shorts found. Verified all of the plugs and ribbons are seated properly and locked in place. All screws installed in the panels.
Watched the screen as I turned it on the first time. First click on- There were some lines that flashed blue for a second and then two more clicks- nothing. Seems I am back at sqaure one. Three clicks of the relay and no worky. This time I did notice a green LED that slowly flashes on a small panel in behind the output board. Could have been flashing before but I never noticed it.
Removed the Y buffer, and turned on, still clicks 3 times and off. Unplugged the X Main and clicks once and apparently stays on. Appears to be an X Main problem again, but I am not sure of much at this point.
Any suggestions before I call it quits on this and blew a bunch of money for nothing?

[capkid]

Re: RCA 42PA30RQ plasma tv problem

Pull your mains and check the transistors and diodes again. I'd probably bag it if you find shorts.