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Tim Nolan
Tim Nolan, TV Repair Technician
Category: TV
Satisfied Customers: 19454
Experience:  Factory trained TV repair technician. U.S. NAVY trained.
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PN43D450A2DXZA samsung plasma tv will not power on. red light

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PN43D450A2DXZA samsung plasma tv will not power on. red light in lower left corner comes on but no power on. small green led in back flashes and hear clicking sounds then it stops and nothing happens.
Thank you for posting your question on Just Answer! I will be happy to help you with this problem. Can you please give us some more information so I can better answer your questions.

-Is the red light in the corner of the tv blinking?
-How old is the unit?

Please give me this information and I will be happy to assist you further.

Thank you,
Tim Nolan
Customer: replied 5 years ago.

Hi Tim,

No the red light is steady. The tv was manufactured in feb. 2011.

I looked at all caps and found none popped or bulged.

The clicking is coming from what looks a small relay on the power board.

There are three of them (2 white, 1 black) and the black one is the only one clicking.

What should i look for next?


Do you know how to use a meter to check DC voltags?

Customer: replied 5 years ago.
yes i do, what do i look for?
You need to check the pins labeled VS and VA on the connectors coming out of the power supply for DC voltage.

Customer: replied 5 years ago.


how much should there be?


About 200 and 60.

Customer: replied 5 years ago.

Ok, there are 2 pins labled VS and 1 VA and 2 ground.

is either ground ok? or do i just go to the vs and va pins?

Yes any GND is fine, you can also use any of the metal on the back of the panel as ground.

Customer: replied 5 years ago.

ok Tim,

VA went up over 200

VS 1 went up over 60

VS 2 went up over 60

But after being plugged in for less than a minut all 3 dropped to almost nothing.

Did they go up and stay or did they come back down?

Customer: replied 5 years ago.

they all came back down to zero


Ok if you disconnect the cable going to the Z-Sustain from the power supply and try again, any change?

Customer: replied 5 years ago.

with cable connected i get about 6 volts on all 3, disconnected, the 2 VS both go to a little over 200 and the VA a little over 60, but then almost immediately, all 3 start dropping slowly to near zero

Ok hook the Z back up and disconnect the Y. Any change?

Customer: replied 5 years ago.



Sorry but I dont know wich is the y, not sure I even had the Z. The one I have been checking is on the top left of the power supply board.

The tan rectangle board on the left side of the tv is the Y sus, the square tan board on the right side of the tv with the two ribbon cables coming out of it is the Z sus.

Customer: replied 5 years ago.

Hi Tim,

no change in power readings with either Y or Z disconnected, but with either or both disconnected, the tv seems to power up fine with no picture. It even makes the welcome tones and the little green LED in back stays lit.

But plug them back in and nothing but clicking. Also with the cables disconnected, I can use power on/off button, but not with them connected.




Do you see all the square black chips on the extreme left side of the tv? If you look close at those chips, do you see any holes or burns in them?


Customer: replied 5 years ago.

They all look fine, no holes or burn marks.


I don't know what the policy is, but if I give you my phone number, would you be willing to walk me through trying to figure this out over the phone?

I am sorry, I wish I could....the TOS I have agreed to with Just Answer prohibits us contacting customers any way other than this site.

IF you want to keep going on the site though I will be happy to help you further, the next step will be to disconnect the board with all those chips on it from the Y sus and try to turn the tv on again.

Tim Nolan and 3 other TV Specialists are ready to help you
Customer: replied 5 years ago.

Ok, before I do that let me give you some more info.

While waiting for your last answer, I decided to try some more troubleshooting. In the pic i sent, the ribbon cable that crosses at the top of the tv, Y to Z? When I disconnect that from the board on the right (Z), then plug in the power cord, the tv powers up, makes the welcome tones, then the screen flashes some multi-colored diagonal lines for a second then goes black.. Also with that cable disconnected, I can turn the tv on and off with the button on the front whereas with it connected, I cannot.

With that cable connected there is no welcome tone or flash of color on the screen when i plug in the power.

Am I going backwards here?

Customer: replied 5 years ago.
what happened here Tim? it says this question is closed. I was not done yet.
No, you certainly are not going backwards, that is the next test we were going to do after the disconncting of the y buffer. Its looking like the Z sus is bad, but we should hook that cable back up and try disconnecting the y buffer. See if anything changes there.

Customer: replied 5 years ago.

Hey Tim, been real busy and have not had time to work on the tv, will be busy for awhile with hunting season. I will accept answer and pay for now but will be back another time to continue.

Thanks for the help so far, Mark