samsung ps50a450p1 dark picture very low contrast

[kobkobk]

need help
samsung 50'' with very low contast and bad picture,test output of power s.-it's look o.k to me.the VS&VA are good Vsc= -195v at y sus. Ve= 100v at z sus

pls ,any idea or where to start?
thanks
kob

[tom66]

Re: samsung ps50a450p1 dark picture very low contrast

Can you supply a picture of the problem? It is most likely an X-main fault.

[kobkobk]

Re: samsung ps50a450p1 dark picture very low contrast

dear sir
i make pictures of the bord and picture display
thanks for your help
kobi

[tom66]

Re: samsung ps50a450p1 dark picture very low contrast

Definitely an X-main problem. The X-main board is this one
https://www.badcaps.net/forum/attach...8&d=1380561602

You can try testing the voltage across those five red capacitors - top left of the photo, five in a row. Voltage across any one (they are all in parallel, you only need to test one.) Should be in range of 50 to 150V. This is the energy recovery voltage. If that voltage is missing or too high, check fuse on X-main.

[kobkobk]

Re: samsung ps50a450p1 dark picture very low contrast

Definitely.
You were right this is indeed z board.
it was missing 15v from the p.s
thank you very much

[tom66]

Re: samsung ps50a450p1 dark picture very low contrast

So, you fixed it? Glad to hear that...