Samsung HP-T5064 picture grainy, dim & washed out

[Robb]

I've got an HP-T5064 with a grainy, dim & washed out picture (see below). The Vs, Va, Vsc & Ve voltages are correct. Adjusting the Vsetup & Vsetdn improved the picture quality a little but it's still very bad.

My first inclination was that the XSUS is having trouble. Has anyone experienced this before?

[freakaftr8]

Re: Samsung HP-T5064 picture grainy, dim & washed out

Thats interesting. What does the black level look like? Id be more inclined to say mainboard.

[freakaftr8]

Re: Samsung HP-T5064 picture grainy, dim & washed out

Perform the test patterns on logic board. Thus will rule out mainboard.

[Robb]

Re: Samsung HP-T5064 picture grainy, dim & washed out

With oscope settings of 5V/div & 1mS/div with 10X probe I got the readings below. Left pic - YSUS, Right pic - XSUS

[Robb]

Re: Samsung HP-T5064 picture grainy, dim & washed out

Black looks washed out too. Not sure what the test patterns on the logic board are.

[tom66]

Re: Samsung HP-T5064 picture grainy, dim & washed out

Go into user menu and adjust brightness/contrast? Also try selecting different picture mode. Avoid Dynamic mode where possible and try Standard or Movie.

Post a picture of the control board and the test jumper can be highlighted.

[Robb]

Re: Samsung HP-T5064 picture grainy, dim & washed out

Adjusting the picture settings didn't change much. I took a few pics since the flash seemed to get in the way and thanks for the speedy replies.

[Robb]

Re: Samsung HP-T5064 picture grainy, dim & washed out

.. and forgot to post them.

[Robb]

Re: Samsung HP-T5064 picture grainy, dim & washed out

My apologies. The pics above are of my main board. The logic board is under it. I now see the 6 pins and should be able to figure out how to run the test from other posts.

[Robb]

Re: Samsung HP-T5064 picture grainy, dim & washed out

I used a HDD jumper to jump pins 5 & 6, disconnected the logic board's LVDS cable going to the main board & powered it on. The display patterns looked like eprogramming's Plasma Break In DVD. Accordingly, it appears I have a bad main board, right?

Perhaps I should have mentioned that I installed new/used Y Sustain and buffers as they were missing when I acquired it.

[Robb]

Re: Samsung HP-T5064 picture grainy, dim & washed out

For reference, I posted a comparison of screenshots

[Robb]

Re: Samsung HP-T5064 picture grainy, dim & washed out

I went ahead and ordered a a ZSUS for the unit but since I have no experience with a bad main board I fear that it might the problem. I'll post the outcome when I get the ZSUS installed.

[Robb]

Re: Samsung HP-T5064 picture grainy, dim & washed out

XSUS swap produced no noticable change. Main board has been ordered.

[Robb]

Re: Samsung HP-T5064 picture grainy, dim & washed out

Swapping the Main board produced no noticable change. The TV now has a new YSUS, Y Buffers, XSUS and Main board yet the problem persists. I find myself in the regrettable predicament of having more invested in the TV than it is worth.

Any ideas? Anyone?

[Robb]

Re: Samsung HP-T5064 picture grainy, dim & washed out

Back to the beginning - I retested the voltage of Vs, Va, Vsc & Ve; Ve was 15v where the panel label says 91v. Unplugged the power cables to the YSUS & XSUS and Ve voltage is still at 15v. By deduction and accepted logic, the power supply must be the culprit.

[Robb]

Re: Samsung HP-T5064 picture grainy, dim & washed out

Quick search on a power supply yielded this court settlement identifying this model as having faulty PSUs.

[tom66]

Re: Samsung HP-T5064 picture grainy, dim & washed out

Ve is provided by X-main on these, I thought.

[Robb]

Re: Samsung HP-T5064 picture grainy, dim & washed out

Apparently the Samsung psu capacitor problem commonly manifests by the unit not powering up at all. I will double check the Ve when I disconnect the power cable going to XSUS. Maybe I got a bad XSUS.

[freakaftr8]

Re: Samsung HP-T5064 picture grainy, dim & washed out

when you disconnected the LVDS cable and you jumper the control board and got the test pattern generator up on the screen did it still look lack of contrast and dim and washed out?

[Robb]

Re: Samsung HP-T5064 picture grainy, dim & washed out

when you disconnected the LVDS cable and you jumper the control board and got the test pattern generator up on the screen did it still look lack of contrast and dim and washed out?

Yeah, I got the usual lackluster image during the logic board test sequence.