Continuing Education Checking Voltages PN50B430P2DXZA Sound Nothing Else

[Michale32086]

In my bid to continue my education on voltage checking, I submit a nice Samsung PN50B430P2DXZA 50" Plasma...

In great cosmetic shape. Previous owner said it just would not power up one day..

Visual inspection shows no blown caps, no burnt components, no visual evidence of impact trauma or power surges.. Two fuses on the Power PCB check out...

When powered up, there is a quick dual click of a relay.. After a second or two, I get the SAMSUNG "boot up" tone.. Power light flashes a couple times (not gonna fall for THAT one again!!! ) and then nothing. No hint of ANY activity on the screen whatsoever...

I got my handy voltmeter (pictured) and hours to kill...

Where do I start??

[R_J]

Re: Continuing Education Checking Voltages PN50B430P2DXZA Sound Nothing Else

Check for shorted fets on the ysus board, (Looking from the back its the board on the left) that board looks familiar.

[Michale32086]

Re: Continuing Education Checking Voltages PN50B430P2DXZA Sound Nothing Else

Check for shorted fets on the ysus board, (Looking from the back its the board on the left) that board looks familiar.

There are three banks of (what I assume are) mosfets on the Y-Sustain board. (Long Board on Left)

Pics attached..

They all look in pretty good shape..

Thanx for the reply..

[Michale32086]

Re: Continuing Education Checking Voltages PN50B430P2DXZA Sound Nothing Else

Additional info on this..

When I have the Y-Sustain board screwed into the metal LCD frame I hear a faint but distinct clicking sound.. Sounds almost like when you hold the button on a BBQs igniter and get that click-click-click-click until the burners ignite..

So, I am thinking short... I pull the screws off the Y-Sustain board and place some paper to hold the board off the metal frame of the LCD. I plug in...

I don't here the click-click-click anymore, but the TV still doesn't come on.. Just the tones.. No display...

I also want to point out that there is a green LED on the T_CON board that blinks constantly when the unit is powered up..

Not sure what it means..

[Michale32086]

Re: Continuing Education Checking Voltages PN50B430P2DXZA Sound Nothing Else

OK Starting on this again this morning...

I have read before where you can disconnect certain video boards and see if you get any kind of light up on the unit. But does that only apply to LCD/LED??

I am leaning towards just replacing the Y-SUSTAIN board as that was where I heard the click-click-click so I am thinking it might be shorted. But I also read here that sometimes if one board on a plasma is bad, you have to replace several boards or else the same will happen..

Any hints or tips would be appreciated..

[Michale32086]

Re: Continuing Education Checking Voltages PN50B430P2DXZA Sound Nothing Else

Further update on this.. I can pick up a replacement Power PCB on this unit for around $50...

Would the odds be in my favor that the Power PCB is the problem, given the symptoms??

[whiz62]

Re: Continuing Education Checking Voltages PN50B430P2DXZA Sound Nothing Else

Search this thread in search drop down, "Samsung PN43E450 Panel flashes no video VS VA drop". I know it is a 43" but some good info on what to check. There is a file on plasma's by tom66 that is very good and it is on this thread.

It helped me getting mine going. Good Luck!

[Michale32086]

Re: Continuing Education Checking Voltages PN50B430P2DXZA Sound Nothing Else

Awesome. I have reviewed all the threads that had PN50B430P2DXZA in it, but there weren't many..

I'll check the thread you mentioned..

Thanx

[whiz62]

Re: Continuing Education Checking Voltages PN50B430P2DXZA Sound Nothing Else

Here is something else I found on plasma with sound but no picture. https://www.youtube.com/watch?v=HNzpnnlkiV4

Hope you get it figured out.

[tw2005]

Re: Continuing Education Checking Voltages PN50B430P2DXZA Sound Nothing Else

Additional info on this..

When I have the Y-Sustain board screwed into the metal LCD frame I hear a faint but distinct clicking sound.. Sounds almost like when you hold the button on a BBQs igniter and get that click-click-click-click until the burners ignite..

So, I am thinking short... I pull the screws off the Y-Sustain board and place some paper to hold the board off the metal frame of the LCD. I plug in...

I don't here the click-click-click anymore, but the TV still doesn't come on.. Just the tones.. No display...

I also want to point out that there is a green LED on the T_CON board that blinks constantly when the unit is powered up..

Not sure what it means..

If the Logic ctrl board led blinks every sec, the TV is on and running.

If it is 2 sec on and 5 sec off, then the TV is in protection .

This is a Plasma TV ,so terms like T-con and LCD frame are a bit foreign to this TV.

Also, I'd avoid running boards unearthed like the y-sustain with paper under it. If that board powers up there's a chance it will blow.

There are guides out there and also in this forum for the main board to be bypassed.

Logic Board Forced Operation

this is an example from a 2009 guide, not sure if correct for this model

If the logic board is in protection though I would not bother trying this as I'd expect it to be Ymain,xmain ybuffers

Step 1- With the Main PCB removed, short pins 1 & 5* on the 24P
ribbon cable to the SMPS from the main PCB to turn the panel on.
This will turn on the secondary voltages of the SMPS. Shorting the
POWER ON connection to ground is the same as the power on from
the power switch.
• Step 2 - Carefully short pins 3 & 4 of the quad connector on the
Logic PCB together. When the panel is powered on, the PDP will
automatically “play” the internal test patterns stored on the Logic
board that would normally be accessed only through the service
menu. This will force the logic board into a loop where the internal
test patterns will be displayed in sequence.
• Step 3 - After the proper pins are shorted, apply power to the AC
input. The TV will power up by itself and if all is well with the logic,
X, Y buffers and address boards, the panel will “play” the test pattern
loop. If everything looks normal the possible problem is the main
board which is the only thing left not in the circuit.
*ALWAYS check the service manual for the correct PS_ON and GND

[Michale32086]

Re: Continuing Education Checking Voltages PN50B430P2DXZA Sound Nothing Else

Not going to be able to get to this this morning, but just wanted to say Thanx, TW and Thanx, whiz...

I'll definitely be jumping on later today..

Thanx again...

[Michale32086]

Re: Continuing Education Checking Voltages PN50B430P2DXZA Sound Nothing Else

OK, getting a start on this...

First off, I am assuming that the Main PCB is the video board (#2 Board) and not the Main Power PCB (#1 Board).. That makes sense else how would I get power to the unit, eh? And the connector shown is the 24 pin connector that I short pins 1 and 5 on...

I have also uploaded a .3GP video that shows the Logic Board LED blinks. I think it's safe to say that it's 1 blink per second..

Finally, the picture of the Logic Board Quad Pin Connector with pins 3 & 4 marked for shorting...

I also confirmed GND and PS_ON via the silkscreen label on the connector.

Everything looks good to go???


EDIT: OK, looks like the video didn't make the cut. But it clearly shows that the blinks are every second without any kind of delay..

[Michale32086]

Re: Continuing Education Checking Voltages PN50B430P2DXZA Sound Nothing Else

OK, with everything set up as indicated, there is little change in the operation of the unit when power is applied..

I still get the click-click of the relay, the LED on the Logic Board still blinks once per sec and there is no display at all..

The only difference is I don't get the Samsung Tones after the click-click of the relay..

So, apparently, the problem is not in the Main PCB....

[tw2005]

Re: Continuing Education Checking Voltages PN50B430P2DXZA Sound Nothing Else

So what voltages are present at the Y and X mains when the logic ctrl bd is blinking? Vs is usually around the 200V mark

[whiz62]

Re: Continuing Education Checking Voltages PN50B430P2DXZA Sound Nothing Else

tw2005 is right. I am just a beginer but know you have to have the voltages present. In my case Vs was supossed to be 209vdc and when powered on it would come up and then drop off rapidly. These folks here on the forum know their stuff and have taught me a lot. Live and learn, only way to be.

[Michale32086]

Re: Continuing Education Checking Voltages PN50B430P2DXZA Sound Nothing Else

So what voltages are present at the Y and X mains when the logic ctrl bd is blinking? Vs is usually around the 200V mark

I am assuming to set my meter to DC???

[Michale32086]

Re: Continuing Education Checking Voltages PN50B430P2DXZA Sound Nothing Else

tw2005 is right. I am just a beginer but know you have to have the voltages present. In my case Vs was supossed to be 209vdc and when powered on it would come up and then drop off rapidly. These folks here on the forum know their stuff and have taught me a lot. Live and learn, only way to be.

DC it is

[whiz62]

Re: Continuing Education Checking Voltages PN50B430P2DXZA Sound Nothing Else

Yes, Volts DC.

[Michale32086]

Re: Continuing Education Checking Voltages PN50B430P2DXZA Sound Nothing Else

211V on #5 and #6 on the Y-MAIN and 211v on #1 and #2 on the X-Main...

[Michale32086]

Re: Continuing Education Checking Voltages PN50B430P2DXZA Sound Nothing Else

Noticable hi-voltage hum on the X-MAIN..