Please help identify burned components on a samsung pn50a550 Y-SUS board

[zape]

see circled
the blown FET is I beleive B14NK60Z because there is another one sitting close
Zener diode is short and resistor is open
Color stripes on the diode are red, brown (gold?) and green.

[R_J]

Re: Please help identify burned components on a samsung pn50a550 Y-SUS board

Post the board number BN**-xxxx . there are different y-sus used in this model

Could the zener colors be RED, YELLOW, GREEN ? if yes it could be RLZ18B

[zape]

Re: Please help identify burned components on a samsung pn50a550 Y-SUS board

There is no BN** number on this board
PCB no LJ41-05571A
Rev 1.1
PBA no LJ92-01535A

[zape]

Re: Please help identify burned components on a samsung pn50a550 Y-SUS board

The zener diode is there for protection so should be something below 30v which is maximum GS voltage for the FET. 18v will work I guess.

What about Resistor? I can read 0 and E but not the middle symbol, 0 Ohm?

[R_J]

Re: Please help identify burned components on a samsung pn50a550 Y-SUS board

The resistor could be 300 which would be 30Ω or 3R0 which would be 3Ω I will se what I can find
Does the other fet have similar parts on its gate?
To me it looks like a 3R0
Maybe someone else has a board to check, I believe BN96-07132A is the same, You can't see the value on any pictures due to the heatsink covering the part.

[zape]

Re: Please help identify burned components on a samsung pn50a550 Y-SUS board

3R0 makes sense. Thanks!

[R_J]

Re: Please help identify burned components on a samsung pn50a550 Y-SUS board

I also see C5008 is bad, so hopefully there is not too much else wrong.

[Tvbob]

Re: Please help identify burned components on a samsung pn50a550 Y-SUS board

Buy a Ysus board and check your buffer boards.
When they sizzle like that, it created a lot of voltage spikes.
That may have damaged the driver circuitry.

[zape]

Re: Please help identify burned components on a samsung pn50a550 Y-SUS board

I'll try to fix this on the component level first. No fun in swapping the boards

[Tvbob]

Re: Please help identify burned components on a samsung pn50a550 Y-SUS board

It is when you get my age...good luck

[DXseekerMO]

Re: Please help identify burned components on a samsung pn50a550 Y-SUS board

Hello fellow Missourian!

I disassembled one of these yesterday with that PBA number. Busted panel but was working.

Both upper and lower Y-bufs checked OK, no shorted IC's.

I'll see about pulling my Y-sus board and taking pix for you in the AM.

Just confirmed in my inventory spreadsheet....I do have this Y-sus

[zape]

Re: Please help identify burned components on a samsung pn50a550 Y-SUS board

The repair was unsuccessful.
Shows pinkish-black broken image instead of blank white test pattern.