Bush Bpdp42hd2 (Samsung S42AX-YB09) screen going off.

[Loz2212]

Hi guys,

Said I'd have a look at this for my old man, the tv turns on and then after a few seconds goes off with what seems like clicking from the PSU board relays. I've measured the Va, Vsc and Vs which all seem ok UNTIL the screen shuts off and the relay clicks then they quickly decay to zero. Assuming I have a short somewhere but my plasma knowledge is nil.. I don't even know which boards are what. I tried pulling boards to see if I could eliminate the board but the PSU won't output any voltages without the boards attached (assume that's normal?).

Read over the odd post about these sets on here and I've heard they're a bit of a ball ache. Any help would be greatly appreciated. Thanks.

[Loz2212]

Re: Bush Bpdp42hd2 (Samsung S42AX-YB09) screen going off.

Photo of the back. Thanks

[Alastair E]

Re: Bush Bpdp42hd2 (Samsung S42AX-YB09) screen going off.

Based on Samsung 42C450 this chassis suffers from X-SUS shorts and this can cause the Y-SUS to fail too. The IGBT's go short.

They, (Makers) recommend changing all three if the X or Y is faulty (Inc Control-Board) during repairs.

Worth pulling out buffers and with everything else still connected try see if it runs as indicated by LED on control-board short flashing and Vs voltage remaining at 200 odd...

[Loz2212]

Re: Bush Bpdp42hd2 (Samsung S42AX-YB09) screen going off.

Thanks for the reply Alastair. Any chance you can tell me which boards are what in the back? Thank you.

[sordids999]

Re: Bush Bpdp42hd2 (Samsung S42AX-YB09) screen going off.

Standing behind the TV ysus is to the left and joined to that is the y buffer board
To the right top is the xsus board and finally the control board is in the middle of the tv

[sordids999]

Re: Bush Bpdp42hd2 (Samsung S42AX-YB09) screen going off.

Look on YouTube for how to test buffers

[crt man]

Re: Bush Bpdp42hd2 (Samsung S42AX-YB09) screen going off.

Hi
To test Y buffer put meter in ohm setting and put probes across
the two large caps if the reading is low IE about 70 ohm's,
or is out of mega ohms then the buffer is shorted,

If the relays click more than once them the two RJH30E2
on the X sus will be short also, that is the two on the
outside of each end on the bank of FET,s

Alan.

[crt man]

Re: Bush Bpdp42hd2 (Samsung S42AX-YB09) screen going off.

Worth pulling out buffers and with everything else still connected try see if it runs as indicated by LED on control-board short flashing and Vs voltage remaining at 200 odd...

If you do that on this set, then if the Fets
on the X sus are not short they will be
after the action.

Alan

[Loz2212]

Re: Bush Bpdp42hd2 (Samsung S42AX-YB09) screen going off.

Fantastic!! Cheers guys. Will be tomorrow now but I will post updates. Thank you

[Loz2212]

Re: Bush Bpdp42hd2 (Samsung S42AX-YB09) screen going off.

Had a quick look tonight at the y-buffer board. Test between both caps was about 5 ohms. I tested along all the pins for the IC's and found one pin on one of the middle IC's was shorted to ground. I'll check over the other components on the X and Y main boards as well. Anything specific to look out for? Thank you.

[crt man]

Re: Bush Bpdp42hd2 (Samsung S42AX-YB09) screen going off.

Just what I said in p7

Alan

[dick_barton]

Re: Bush Bpdp42hd2 (Samsung S42AX-YB09) screen going off.

If you use the search and put in "Bush Bpdp42hd2" there are several threads which may help you.

[Alastair E]

Re: Bush Bpdp42hd2 (Samsung S42AX-YB09) screen going off.

If you do that on this set, then if the Fets
on the X sus are not short they will be
after the action.

Alan

Err--

Just pulling Buffers and running this chassis with everything else still connected--Will NOT kill the X-SUS IGBT's! Ive seen many of these, even owned one for a while...

--Dunno where you got That from.

[ReeceyBurger123]

Re: Bush Bpdp42hd2 (Samsung S42AX-YB09) screen going off.

Ali he gets it from some newer panny sets removing the Ybuffer can kill the Ymain and possibly the Xmain too I have read up.

[Alastair E]

Re: Bush Bpdp42hd2 (Samsung S42AX-YB09) screen going off.

OK--Right--

But we are looking at ancient Sammy tech here....

[Loz2212]

Re: Bush Bpdp42hd2 (Samsung S42AX-YB09) screen going off.

Thanks guys. So the x-sus IGBT's need checking and a new y-buffer board?

[crt man]

Re: Bush Bpdp42hd2 (Samsung S42AX-YB09) screen going off.

Err--

Just pulling Buffers and running this chassis with everything else still connected--Will NOT kill the X-SUS IGBT's! Ive seen many of these, even owned one for a while...

--Dunno where you got That from.

I done it as an experiment with a set I have, and that is what happened.
Done seven of them.

Alan.

https://www.badcaps.net/forum/showth...ight=bpdp42hd2

[Alastair E]

Re: Bush Bpdp42hd2 (Samsung S42AX-YB09) screen going off.

Hmm--Ive done 30 or 40 of the bloody things over the years...

[crt man]

Re: Bush Bpdp42hd2 (Samsung S42AX-YB09) screen going off.

Hmm--Ive done 30 or 40 of the bloody things over the years...

But you are a professional are you not.

I just do this as an interest, it was the first plasma
I had done, and done seven in about a six month period,
the only other flat screen was an led with poorly
seated ribbons.

I found some strange things with this plasma,
that did not check out with threads on other
sets.
As I said I done it as an experiment and I
was not talking out of the top of my head

Crt's is my thing.

Alan.

[Alastair E]

Re: Bush Bpdp42hd2 (Samsung S42AX-YB09) screen going off.

Aye--Flatties is my profession--CRT's a hobby Started out in the era of the G8 and Pye Hybrid!

CVC2 with replacement CRT and TV62 with dodgy CRT heater, and TV125 in collection--Still hoping one day to find a G6 (G22K511/2) ....