PN42B430P2DXZC Audio No Pic Voltage good

[dcapper]

I have been reading different posts about Samsung plasma panels and they all have different problems. I have perfect voltage levels on my Ysus, Xsus, and power supply. I also metered all the gates, diodes, and caps on my Ysus and Xsus. None have shorts. But on my Y buffer D5401, D5402, and D5403 all are shorted but when I lift one side they all read good. But there is inline resistors stamped 470. When I meter them I get 6 ohms, the same as the diode. So I don't know if this is a problem or not. I attached some pics. Maybe I have a bad panel? The bright mark at the top is from my flash.

EDIT: I do have sound.

[dcapper]

Re: PN42B430P2DXZC Audio No Pic Voltage good

I have beating my head against the wall on this one. I took some new pics. Pic 1 is when you first turn it on and pic 4 is after you leave it on for a few mins. Thinking I missed something, I re-metered everything and cannot find a short or blown part anywhere. Anyone have any ideas?

[dcapper]

Re: PN42B430P2DXZC Audio No Pic Voltage good

Adding to my problem. I tried the control board test as per Tom66's thread, no test pattern, same problem. My voltages never fluctuate. I tested the y buffer chips and there was no shorts. The green light on the control board blinks once per second, which is what the service manual says it should. There is a test point on the Ysus that says VSCH and it fluctuates around 15v. The Vscan is 190v like the panel says it should be. When I turn it on and get that funky display, the power light on the front blinks red for a bit then turns off and no other lights come on. I also took a flashlight to the whole panel and there is no cracks. Can someone tell me if there is something I missed?

[tom66]

Re: PN42B430P2DXZC Audio No Pic Voltage good

resistor marked 470 is actually 47 ohms (47 x 10^0). Typically 6 to 8 are in parallel so that gives you your 6 ohms right there.

Vsch should be 120 to 150V. Is this not the case? Isolate the buffer and measure without it. What does Ve measure?

[dcapper]

Re: PN42B430P2DXZC Audio No Pic Voltage good

resistor marked 470 is actually 47 ohms (47 x 10^0). Typically 6 to 8 are in parallel so that gives you your 6 ohms right there.

To me, it looks like a control board issue or some signal not reaching the X-main. It is very odd, that's for sure.

Thanks Tom. There is other resistors in the general area so they must be in parallel. Is it normal for a control board to only show that bottom left corner and the rest of the display blank?

[tom66]

Re: PN42B430P2DXZC Audio No Pic Voltage good

No, it's not normal at all, something is wrong. The control board is the only board in the set that has control over BOTH the X and Y of the panel (columns and rows) so I -think- that is the fault... but I've really never seen this before so I'm not sure what to make of it.

[dcapper]

Re: PN42B430P2DXZC Audio No Pic Voltage good

I paid $60 for the tv. A control board is around $30 shipped. So it will be a $100 test. I'll order one off ebay and let's see if it will work.

[tom66]

Re: PN42B430P2DXZC Audio No Pic Voltage good

Are you going for a BN44-###### control board number, or a PN42B430 board?

You can also use PN42B450, and the Insignia/Vizio/etc. boards.

However you cannot use a 50" board.

[dcapper]

Re: PN42B430P2DXZC Audio No Pic Voltage good

The numbers on the board I have is LJ92-01616/01617 and LJ41-05903a. It says under the LJ92 number, (42/50)

[tom66]

Re: PN42B430P2DXZC Audio No Pic Voltage good

The board will be programmed with 42" or 50" firmware, as far as I know, you cannot convert a 50" board to a 42" or vice versa, so you must check with the seller the board was a pull from a 42" panel.

[dcapper]

Re: PN42B430P2DXZC Audio No Pic Voltage good

Lucky I was just going order the first one. I'll make sure before I order.

[dcapper]

Re: PN42B430P2DXZC Audio No Pic Voltage good

I decided to beat this tv up again. I didn't order a logic board yet. It's blinking green normally. I did unplug the ribbon cable from the Xsus to the panel and the picture didn't change. I noticed that my voltage on the Y buffers are all 149v except for the first 2 pins on the top connector. Dunno if that's normal. Anyone have anything I should try? Or should I be taking the loss and tossing it.

EDIT: I noticed there is no red light behind the cover of the digital audio connector. I'm wondering if it's the main board or the logic board.

[Alastair E]

Re: PN42B430P2DXZC Audio No Pic Voltage good

Have you tried the test-function on the logic board--disconnecting main and shorting the jumpers on the logic?

[dcapper]

Re: PN42B430P2DXZC Audio No Pic Voltage good

I tried to get to the test screen and I still get the same picture.

[dcapper]

Re: PN42B430P2DXZC Audio No Pic Voltage good

Well I broke down and bought a control board. Tri State module thought it would be that board. Received it and it's doing the same thing. Is it possible for a main board to do this?

[dcapper]

Re: PN42B430P2DXZC Audio No Pic Voltage good

I'm not letting this tv beat me. tw2005 suggests I try the x main next. Going to order one today. I just received another Samsung doing the exact same thing. Must be a common problem. I'm surprised nobody else has reported a problem like this.

[dcapper]

Re: PN42B430P2DXZC Audio No Pic Voltage good

Running out of boards! I bought a brand new x main. No go. Only thing left is the Ysus and the main board. I know buffers wouldn't do that. Unless it's a panel failure. I'm getting ready to give up and cut my losses on this one.

[paulstef]

Re: PN42B430P2DXZC Audio No Pic Voltage good

Running out of boards! I bought a brand new x main. No go. Only thing left is the Ysus and the main board. I know buffers wouldn't do that. Unless it's a panel failure. I'm getting ready to give up and cut my losses on this one.

Did you ever solve this problem? Have the same TV with the same problem.

[paulstef]

Re: PN42B430P2DXZC Audio No Pic Voltage good

Does anybody has an idea of how to troubleshoot this fault? I have the EXACT same problem. All DC voltages are oK, VS (207), VA (54), VSC(-190), 15V, 5.3V.

Control board seems to blink normally. I don't know where to go from here. Nothing heats abnormally. Mainboard reacts to button presses.

Initially I have only two defective MOSFETs + L6599D controller replaced on the PSU board.

video of picture
https://youtu.be/ZFsLaR1o46s

[tom66]

Re: PN42B430P2DXZC Audio No Pic Voltage good

Run test patterns by jumpering pins 3 and 4 on logic board test header.

It's not the Y-main or X-main or power supply.

It can only be control board, panel, or main board. If test patterns still have same problem, it is panel or control board.