Samsung PN50B430P2DXZA

[ned1]

Re: Samsung PN50B430P2DXZA

Got Samsung remote, went to service mode. There is Mstar test pattern, FBE pattern and Logic pattern test. It skips FBE pattern ( I believe this is Main board test) but I can load MStar and logic. Both patterns goes try bunch if different screens and picture is bad on all of them. What is MStar testy anyway.
Is there a way to enable FBE test pattern?

[tom66]

Re: Samsung PN50B430P2DXZA

Mstar is main board.
Logic is control board.
FBE is for 100Hz TVs, it is on control board or main board.

[ned1]

Re: Samsung PN50B430P2DXZA

So both are bad signals, does this looks like bad panel?

[tom66]

Re: Samsung PN50B430P2DXZA

Well, given I have never seen a bad panel do that, I hasten to call it that.

Your X-main is working. I have seen the exact same effect when the electrode FPCs (the orange ribbons) aren't connected to the X-main.

It is possible, though very unlikely, that the connection between the FPC and the panel is bad. However, the reason this is unlikely is that all the lines are connected together, into one common point; a small damage to the FPC won't make any difference.

[ned1]

Re: Samsung PN50B430P2DXZA

According to test patern I may need to order both main and logic board. I already replaced logic so I am hating to do again. Maybe I should start looking power supply what glitcher suggested, it just does not make any sense all voltages are correct out of power supply.

[tom66]

Re: Samsung PN50B430P2DXZA

Your power board is fine, there is nothing wrong with it. I also think your logic board is most likely OK.

[ned1]

Re: Samsung PN50B430P2DXZA

What about x-main buffer board. There is nothing on it that can go bad, all it does connects x-main to panel ribbon cable. How about those boards on the bottom of TV, do they have anything to do with picture quality?

[tom66]

Re: Samsung PN50B430P2DXZA

The boards on the bottom deal with the exact image to be displayed, but they don't affect its colour or performance. (Data driver boards.)
The X-main buffer could cause this issue if the connections on it have cracked solder joints.
Also inspect the orange FPC coming out of the X-main for tears/damage/etc.

[ned1]

Re: Samsung PN50B430P2DXZA

Tom the orange cables from x-main buffer to panel gets 76V. X-main is 88V.

[ned1]

Re: Samsung PN50B430P2DXZA

I removed both orange cables from x buffer board, still 76V. I saw jump from 88V down to 76 when I powered TV on.

[tom66]

Re: Samsung PN50B430P2DXZA

Something is wrong somewhere then. Please remove both boards and inspect them for damage: cracked solder joints, broken tracks, cracks in the board, etc.

[ned1]

Re: Samsung PN50B430P2DXZA

Ok I disconnected x main from x-buffer and again 76V. The test point on Xmain reads 88V but the connector to X-buffer reads 76v . When I remove T-con connector from X main I got only 9V

[tom66]

Re: Samsung PN50B430P2DXZA

Do you still have the scope? Try probing the point on the X-buffer marked OUT. If it's notably different from the other waveform at that blue capacitor, I'd say something is disconnected/broken somewhere... that would be an interesting one.

[ned1]

Re: Samsung PN50B430P2DXZA

I will bring scope tomorrow

[ned1]

Re: Samsung PN50B430P2DXZA

Do I connect scope to any of these pins on white connector?

[tom66]

Re: Samsung PN50B430P2DXZA

Check the pad marked OUT, you can take the probe hook off the end of the probe and touch in on the OUT pad directly.

[ned1]

Re: Samsung PN50B430P2DXZA

The pad market out is empty hole with solder on the back of board. Should I run wire thru and solder on the back and connect scope hook there?

[ned1]

Re: Samsung PN50B430P2DXZA

Never mind I misunderstood your previous message.

[ned1]

Re: Samsung PN50B430P2DXZA

Here is the picture of the waveform taken from x-buffer out.

[ned1]

Re: Samsung PN50B430P2DXZA

Both waveforms, from X-buffer and from X-main