Samsung PN43D450A2D

[TheSniper]

Re: Samsung PN43D450A2D

Does the TV power on if the main board is plugged in but the PDP T-con is disconnected? (The PDP T-con is the small board which interfaces with the main, Y sustain and Z sustain boards, as well as the X buffers.)

@ Tom66
Mine is exhibiting similar issues When turned on the lower relay on the SMPS board clicks several times.(off and on randomly) NO audio (start up sound). IF I disconnect as you mentioned above. I get a startup sound and no more clicking.(except 2 clicks which sounds normal) But no video etc.
Thoughts?
TIA
TheSniper

[tom66]

Re: Samsung PN43D450A2D

Which boards did you unplug?

[TheSniper]

Re: Samsung PN43D450A2D

Which boards did you unplug?

Only the logic board from the SMPS board I left all other cables intact

[tom66]

Re: Samsung PN43D450A2D

With logic connected, look at flashing light on logic board.
Does it blink approx once a second or approx once every five seconds?

[TheSniper]

Re: Samsung PN43D450A2D

With logic connected, look at flashing light on logic board.
Does it blink approx once a second or approx once every five seconds?

Right at plug in(power up) it briefly flashes. then a bright flash and then one last flash all within the first 3. seconds or so. then nothing(no more flashes). All with all cables plugged in

[tom66]

Re: Samsung PN43D450A2D

OK, sounds like possible main board fault. Disconnect power connector between main board and power board. Main board has the HDMI ports on it. Then check LED behaviour.

[TheSniper]

Re: Samsung PN43D450A2D

OK, sounds like possible main board fault. Disconnect power connector between main board and power board. Main board has the HDMI ports on it. Then check LED behaviour.

If I disconnect the power cable from the SMPS to the Main board I get abso nothing. no clicks no blinking no anything. as if everything is dead.

[TheSniper]

Re: Samsung PN43D450A2D

ideas/thoughts?

[TheSniper]

Re: Samsung PN43D450A2D

I will add:
If I remove the Xboard pwr cable : Same results bunch of cllicking
If I remove the Yboard pwr cable: the unit appears to power up music but no pic.

Also I tested On the SMPS:
on constant power all cables connected:
PS-on =3.29v
Stby = 5.1v
D5.3 = nada
D15V = nada
However If I test pin during power on I get the correct voltage upon boot up
voltage seems to be correct when SMPS relay clicks then afterwards No voltage at test pin.

-TheSniper

[ddg421985]

Re: Samsung PN43D450A2D

Does anyone have the schematic diagram for the Samsung Pn43d450a2d? My relay chatters too, but the voltage on the relay is fluctuating. My 5 volts on the relay is 4.9, but my pull down pin still has voltage on it(something is not turning the transistor on) as the base voltage on the relay transistor is low also. After being plugged in for 30-45 seconds, the relay chatter changes to louder and slower. Thinking maybe a bad cap or bad transistor/ic. With no schematic I'm kind of flying blind. Any help would be greatly appreciated.

[tom66]

Re: Samsung PN43D450A2D

What is BN44-xxxxxx[A-Z] number on the board?

[gnossdrawkcab]

Re: Samsung PN43D450A2D

Hi guys,

I have the same issue as crashp3 had with a slight variation. My Samsung PN43D450A2D is clicking when the power cord is plugged in and the TV will not power on. The red light on the front of the TV is solid red and the clicking is constant. The clicking only occurs when the Main Board (AV board) is plugged in to the CN801 connector. I checked the PS-ON pin with my multimeter and I'm seeing 3.7V. I checked the STBY pin and I'm seeing 0V. I noticed crashp3 had seen 5V or so across this pin. I'd like to just buy a new main board like he did which seemed to fix his problem, but wanted to see what you guys thought first about this difference in voltage that I'm seeing.

Thanks so much for your time.

[newtothis]

Re: Samsung PN43D450A2D

Unplug mainboard from PSU and check STBY again.

Black to chassis and Red to pin

[gnossdrawkcab]

Re: Samsung PN43D450A2D

Unplug mainboard from PSU and check STBY again.

Black to chassis and Red to pin

Woops. I was measuring with the mainboard unplugged and that's when I read 0V across STBY. When I plug in the mainboard I do see 5V across STBY but the PS-ON pin seemed to drop to 3.2V now.

[gadgetman1966]

Re: Samsung PN43D450A2D

I had the same clicking on my power supply, no Tv. Same exact model number.PN43D450A2D.
When I opened it up, I found 1 swelled 1000uf cap on the power supply, so I replaced both the 1000uf caps. Plugged it in and the same thing. Clicking coming from same component as the picture in a tom66 post on the first page in this thread.
The green light on the control board below the power supply is blinking a lot when it tries to start and it is clicking.
So I unplugged main board and nothing at all. Plugged main back in.
Unplugged Control board power connector and still clicking. Then I unplugged x-board power connector from the xboard and no more clicking. The green light stays solid for 5-6 seconds and then goes off for 3 seconds.

Just by from what I have read in this post, common sense, and trial and error I would say my Xboard is bad.

Is my elimination process wrong?
Any ideas you might want to share?
Thank you for your time.

Power supply board BN44-00442A
x main 42DH

[gadgetman1966]

Re: Samsung PN43D450A2D

Got the new X-Main board today and installed. The TV turned on right away.
Upgraded firmware from version 1005 to version 1006.
Samsung PN43D450A2D works awesome again.
Thanks to this forum and this thread for the info to help pin point the problem.