Samsung 50" PS-50Q97HD Plasma TV - No display

[safesurfer65]

Hi all

Got a 50" Samsung 50" PS-50Q97HD that has no display. Seems to start up ok but a completely black screen. Green light on the Y-Sus board comes on and I can see the red optical output on the main board lighting up. I've checked the Va and Vs on the PSU and they measure 63v and 207v as they should. Any tips on how to verify if the Y-Sus and/or buffer boards have failed ? Any help much appreciated.

See photos (sorry not great)

Thanks

Mark

[tom66]

Re: Samsung 50" PS-50Q97HD Plasma TV - No display

Green on Y-main means protection fault likely shorted Y-buffer board.

[safesurfer65]

Re: Samsung 50" PS-50Q97HD Plasma TV - No display

Many thanks Tom

Right enough, I disconnected the buffer boards and the TV still switches on but no green light on the Y-Sus. Does this suggest the Y-Sus is good ?

Cheers

Mark

[sordids999]

Re: Samsung 50" PS-50Q97HD Plasma TV - No display

you could test your boards by using one of toms tutorials

https://www.youtube.com/watch?v=51SZsfH60EY

[freakaftr8]

Re: Samsung 50" PS-50Q97HD Plasma TV - No display

Agree. Try disconnecting upper buffer board from ysus and see if the bottom of the panel lights up. Very top IC on the upper buffer is known to fail. Of course make sure no shorted MOSFETs on ysus.

[safesurfer65]

Re: Samsung 50" PS-50Q97HD Plasma TV - No display

Thanks guys,

Disconnected top buffer board, no green light on Y-Sus but no display on the lower of the screen. I can hear a slight buzzing coming from the Y-Sus. Any pointers on checking it for faults, mosfets etc ?

thanks

Mark

[tom66]

Re: Samsung 50" PS-50Q97HD Plasma TV - No display

Just check for short circuits on the individual MOSFETs.

[safesurfer65]

Re: Samsung 50" PS-50Q97HD Plasma TV - No display

Just check for short circuits on the individual MOSFETs.

Sorry to be a pain but how do I go about testing the mosfets ?

thx

[tom66]

Re: Samsung 50" PS-50Q97HD Plasma TV - No display

Use the continuity range to check all pairs of pins for shorts. For more indepth testing info there are tutorials on the internet.