Samsung PS43D450 X-main compatibility

[tom66]

Am working on a Samsung PS43D450

Have found bad X-main board (seems to be a common fault), however, mine is rev 1.6 and most on eBay are rev 1.8. I see the difference is mostly an additional resistor and a change of the inductor.

Samsung PBA part number is the same for both...

Anyone know if there's an issue using the rev 1.8 board in a set originally using a rev 1.6?

[clark97]

If its final output fets that are gone its likely you have a faulty screen and new board will blow aswell. Noticed some of the different versions have extra fets on output on reverse of board.

[tom66]

If its final output fets that are gone its likely you have a faulty screen and new board will blow aswell. Noticed some of the different versions have extra fets on output on reverse of board.

I've repaired the PS42B450 before which had a failed X-main, new one fixed it. I'm pretty sure the panel's OK because I'm getting good waveforms to the buffer (until control board senses no X-main and shuts it off), if the panel were bad I would damage the buffer (Y-scan electrode to Y-com short I presume) but that's not happened.

Apparently there's a firmware update to fix the common X-main failure on this chassis.

Final IGTBs blew, as did YER FET. They've only got four DPAK IGBTs for driving the panel (two for each rail) and with the tiny heat pad it's no wonder they fail.

[tom66]

New X-main in, set now works a charm. Panel's good. Buzzes quite loudly, though on bright images -- not so audible at 10 ft but still distracting.