Question about samsung test patterns.

[Shinju]

Ok, I cannot get a definite answer as to what each pattern means and what use it has to reflect what part of the panel has failed.

For example I have a LN55A750 that has severe reds in the black/dark areas of the video feed/idle screen.

When I run test pattern DDR pre/post the picture is perfect no reds in the blacks ect. This panel only has those 2 test patterns.

Others I have worked on have

LOGIC
FBE
FRCS
READ
LDAsic


Does anyone here know for sure what each test is for? Or have a link to a manual that has these tests and what each one is for and an explanation of what each test is for and what each test does at a Componate level for success and failure.

Thanks!

[tom66]

Re: Question about samsung test patterns.

DDR before - data before tcon FRC (frame rate converter, 120Hz etc)
DDR after - data after tcon FRC

It's probably a main board fault. Do you have a picture?

[Shinju]

Re: Question about samsung test patterns.

@Tom66

This is the only photo I have. As you can see the black bars got a red hue to them.

Funny part is when I smacked the back of the panel the issue disappeared, came back for awhile and I did it again and now its been working fine.

Makes me wonder if there is a dirty connection or a ribbon cable snap lock that is warped/broken due to heat. Panel has 12,000 hours on it.

The DDR tests were ran while the Panel was in its "Red HUE" state, clear as day when DDR/Post/Pre were ran.

This Panel is a beast, and a early adaptation of FRC and has a huge metal shield covering all the boards behind the piano black plastic rear cover. Not looking forward to breaking this one down!

(Not sure why the photo is turned, its not that way when viewing it outside of the site)

[tom66]

Re: Question about samsung test patterns.

Is the LVDS cable OK? I've had failures caused by that cable that look similar.

[Shinju]

Re: Question about samsung test patterns.

I will know more once I crack it open. I was using this panel as an example as to what may look like a bad panel might not be and run these test patterns to determain the hardware fault.

I will make a new thread on this one later.

But the LVDS will be the first thing I check! Thanks Tom66!