SAMSUNG PS42C451B2D No picture,no sound - fixed

[tw2005]

Hi, Picked up a Samsung PS42C451B2D plasma TV. Usual deal, shuts down, no picture or sound. Logic board quits with a slow blink indicating failsafe.

Disconnecting Xmain, could get powerup and sound, then tried replacing the IGBTs only xmain, blew them, killed Ymain, buffer seemed ok.

researching this forum, there's a few posts especially the RCA 42PA30RQ, same panel and boards.

Pretty clear reading them the only sure way to nail this is the Xmain,Ymain,Ybuffer swap otherwise it appears you simply waste time and money blowing boards.

Did this, sure enough, it works. as it turned out the buffer was fine so only really needed the others.

Firmware upgraded to 1024 (was 1023), not sure if this is worldwide firmware but this was Australian model.

I got the parts real cheap from payless components, he's since cleared out of the ones from the RCA & Viore brands which is no surprise since the X was about $11 and the Y about $13. If you searched only by samsung it would have been much more but they're the same. Buffer was $30, pitty I did not have the courage to trust mine otherwise would have been a working set for under $100.

Have to admit I'm not a Samsung fan but does have very good picture and reasonable sound with media player ability as well.

Below is some other models shown as the same panel and boards.

ybuffer LJ41-08594A LJ92-01739A (sticker 739c)

xmain LJ41-08591A LJ92-01736A

ymain LJ41-08592A LJ92-01737A


ELEMENT
ELPCFT421

INSIGNIA
NS-42P650A11

RCA
42PA30RQ

SAMSUNG
PN42C430A1DXZA, PN42C450B1DXZA, PS42C450B1WXXU

VIORE
PD42VH80


Panel Sticker Number:

S42AX-YB09, S42AX-YD13

Panel Manufacturer:

Samsung

[capkid]

Re: SAMSUNG PS42C451B2D No picture,no sound - fixed

Yeah, board swapping is the way to go on these TVs. I tried to get cute by changing out the IGBTs on my first couple Samsungs of this ilk, and I ended up in TV repair hell.

[tom66]

Re: SAMSUNG PS42C451B2D No picture,no sound - fixed

Same experience myself -- I've actually only found some with shorted IGBTs. Most I couldn't actually track down a fault.

[tw2005]

Re: SAMSUNG PS42C451B2D No picture,no sound - fixed

Same experience myself -- I've actually only found some with shorted IGBTs. Most I couldn't actually track down a fault.

i did not think this one had any at first, sometimes I think i'm losing my mind but very soon after both had shorted transistors,

[tw2005]

Re: SAMSUNG PS42C451B2D No picture,no sound - fixed

Yeah, board swapping is the way to go on these TVs. I tried to get cute by changing out the IGBTs on my first couple Samsungs of this ilk, and I ended up in TV repair hell.

I think it was this one that was pretty convincing. I was quick to call it quits this time for board repair.

Your Y-main may have been damaged by the faulty X-main; the part you got on eBay was probably fine...before it was installed in your TV. It probably got damaged by the Y-main, which was probably damaged by your original X-main. It can become an infinite loop. Trust me, you need to be very careful when testing these particular TVs. I'd do most of the testing with a meter and skip the voltage tests in relation to the mains. I'd only test the power supply with none of the mains connected to it.

Edit: Again, you may be looking at replacing the Y-main, Y-buffer, and X-main ALL AT ONCE again to get it working.

[tom66]

Re: SAMSUNG PS42C451B2D No picture,no sound - fixed

Combined energy recovery + very lackluster IGBTs (like maybe one for each main switch portion; Panasonic use 2 or 3.)