This guy has an RCA 42PA30RQ

[Bling23]

Re: This guy has an RCA 42PA30RQ

Well there are times when you have to set a limit on time wasted on a repair. I've wasted a lot of time and money on this Plasma Tv so It's going to the landfill. I'll salvage the good boards and sell them...Thanks to all who helped me with their thoughts and knowledge ..

[tom66]

Re: This guy has an RCA 42PA30RQ

Shame to do that. At least sell it on craigslist or ebay as faulty so someone else can have a go.

[Bling23]

Re: This guy has an RCA 42PA30RQ

Well alright Tom!!! I'll keep at it but the person I'm fixing it for is probably wondering why I haven't fixed it yet.

[tw2005]

Re: This guy has an RCA 42PA30RQ

Vince I tested all the boards before installing them. Problem is when I have all the boards installed, I get buzzing sound from x-main. Then I end up shorting out the mosfets on both the y and main. And I can't find those fets here or anything comparable. So I have to wait forever to get them shipped from main land China....if I replace the whole Y main,that will be my forth board And third for X-Main. Right now Im on holding pattern until the mosfets come in

What has my curiosity is what you stated above. I can't help thinking the panel is shorted and maybe that's why mosfets keep shorting and you've had no luck.

I've been in a similar situation, unable to find any shorts on buffers, y or x main. Smoked 2 good buffer boards dicking around with it and short buzzing almost sounded like electrical arcing noises which at first sounded like the boards but in the end I decided it was from the panel.

That was in a SANYO with similar samsung panel and boards. No obvious crack in the panel either but it could have been concealed or simply panel failure. it's the only one I lost money on and failed to fix.

Don't want to dampen your spirit but not every repair is a winner. Hope you prove me wrong

[Bling23]

Re: This guy has an RCA 42PA30RQ

Tw2005, I tend to agree with you. I honestly have checked very circuit on the boards for shorts and found none. I've checked and tested every diode,cap, resistor, transistor etc, and only find the mosfets blow. I honestly believe I do have a shorted panel causing the y and x main to short it's mosfets out. I also had my suspicion that the buzzing sound was coming from the panel and not the x-main.

[Bling23]

Re: This guy has an RCA 42PA30RQ

Ok I finally recieved the RJH30E2 mosfets for the x-main. I tested them prior to soldering them and they tested good. I soldered them onto the x-main and tested them again in circuit and they tested good. Waiting on the RJP30E2 IGBT to arrive for the Y-main board.

[Bling23]

Re: This guy has an RCA 42PA30RQ

The RJP30E2 arrived for the Y Main board. I tested them out of circuit and they are a go.
Time to install them on the Y main and see what happens.

[capkid]

Re: This guy has an RCA 42PA30RQ

I hope it turns out well for you. Is this model one of those Samsung-based plasmas? If so, I've found that some of these Samsung-based thin-profile plasmas can be a pain if you tinker too much with them. I've blown a couple Y-Sus's and buffers during testing.

Some of the SMT components on the back side of the Y-main and X-main boards seem to go bad. Replacing the through-hole components has only worked for me once, and that was on an X-main that had very few SMT items. Other times, I've ended up with a repeat failure. I now opt to replace whole boards with new in most cases, since board prices are relatively reasonable.

Edit: I don't trust the Y-buffers in these TVs, so I replace the Y-buffer and Y-main as a set if the Y-main fails. The chips on the Y-buffer don't seem to blow, but there are an inordinate amount of SMT components on some of these buffers, and I suspect one or more of these components fail.

[Bling23]

Re: This guy has an RCA 42PA30RQ

I've replaced the Y-buffer..on my third of forth y-main and on my second x-main. But thanks for the info capkid. Here's what happened on this last attempt.

Test 1...Everything was connected on the set. No shorts or shorted components after methodically testing all the boards. If figured this time I would started the tv with everything connected on the tv minus the panel ribbons that connect to the X-main.

Results= with TV powered up, I hear the relay clicks on and off. The blue LED light is steady not blinking. However, the ribbon cable from the logic board to the Y Main still causes my vs and va volts to drop. I did not hear the buzzing sound from the x-main board.

Test 2. Disconnected the logic board to Y main ribbon cable. Ribbon cable from panel to X main still left disconnected .

Results= I have Vs and Va voltage where it should be (207vs and 54 Va) Ve 91v. Checked Vscan and it was -177 and for this set it states Vscan should be -197. But still no picture or sound at this point and I haven't blown any RJH30E2's on X main or RJP30E2's on Y Main.

Test 3.. I adjusted the Vscan to -187 and not -197 because last time I adjusted the Vscan to -197, I started getting the multiple clicks from the relay which is a sign that I shorted out transistors on Y-main. panel ribbon still left not connected to X main board and logic ribbon not connected to Y main.

Results- no buzzing sound from X main and Vs, Va and Ve are fine. But still no sound or picture..well blue screen would be a better word.

Test 4.... This time I disconnected the panel ribbons from the Y buffer board, no logic board ribbon connected to the Y main and I connected the panel ribbons on the X main and disconnected the logic ribbon from the X main.

Results... Vs,Va and Ve are fine, no buzzing sound coming from the X main and no multiple clicking from the PSU relays. But still no blue screen or sound.

Test 5.... I connected the logic board ribbon to the X main, the panel ribbons are left connected to the X main, the Y buffer board is left not connected to the y panel ribbons and the logic board ribbons are left not connected to the Y main.

Results...I heard the buzzing sound coming from the x main then for a split second I heard static sound from the speakers , then the relay started doing the multiple clicks. I powered off the set. Unplug it then re plugged the tv. Powered it up and I got the multiple clicks from the relay,no buzzing sound from the x main. I pulled the X main board off the tv and sure enough, the two RJH30E2's were shorted.

The static sound from the speakers was a plus. However, I didn't blow any transistors on the x main when I didn't have both the logic board ribbon and the x panel ribbons connected to the X main board .

[Bling23]

Re: This guy has an RCA 42PA30RQ

I need schematics for this RCA 42PA30RQ!!! Does anyone have it or know where I can could find them?

[tom66]

Re: This guy has an RCA 42PA30RQ

Samsung do not and have never published schematics for their PDP modules, because the parts are intended as replace only, not repair... as short sighted as that may be.

[Bling23]

Re: This guy has an RCA 42PA30RQ

Thanks Tom

[Bling23]

Re: This guy has an RCA 42PA30RQ

Ok folks I emailed Damon who wrote a great ebook on plasma TVs. According to Damon, and I quote "if there is a short in the panel electrodes this can over stress the drive fets"

[tom66]

Re: This guy has an RCA 42PA30RQ

That sounds correct to me. It's relatively common with newer panels, usually after a light impact which doesn't crack the panel.

[Bling23]

Re: This guy has an RCA 42PA30RQ

Going to end my repair efforts on this tv and start on a new one that's hopefully the fixable

[miyagi]

Re: This guy has an RCA 42PA30RQ

Can anyone tell me if Q5003, Q5007 & Q5008 are all RJP30E2's on y-main ( 42u2p), this board was worked on before,