Samaung 43" Plasma PN43D450A2D will not power on

[khi11]

I have a Samsung 43" Plasma TV PN43D450A2d that this past weekend suddenly will no longer power on. It has always been plugged into a surge protector.

Currently when I plug the TV in, the red standby light will blink several times and there are a few clicks as if the TV is attempting to start up but fails and then re-attempts. After several of these cycles, the standby light stays lit and the TV is not responsive to the remote or manually pressing the buttons on the set. No sound is heard or video is available. I have to unplug and re-plug the TV to for it to re-attempt start-up.

I removed the back panel and looked at the Power supply and do not see any swollen or leaking capacitors.

I have also test the voltage across the Vs and Va test points while the TV was attempting to start after plugging in the TV. The Digital meter would initially start at 0 then go to 1, then back to zero while the clicking was occurring and then settle back to zero. this happened in both tests.

I am pretty sure this means the Power Supply board is shot and was going to order a replacement. (I do not want to try to troubleshoot individual components.)

Does this sound correct? or could something else be causing this?

[tw2005]

Re: Samaung 43" Plasma PN43D450A2D will not power on

what's the Logic control board doing, is the LED doing a slow blink once every 5 secs? I'd be thinking more likely to be in protect and a bad xmain(or y/ybuffers)

I think there's a fast track guide for this. If you disconnect both x & y main, back probe the Vs at the PSU and watch on powerup. Shuld briefly come up then drop off. these also go protect if x or y main disconnected

[khi11]

Re: Samaung 43" Plasma PN43D450A2D will not power on

So I should disconnect X & Y boards and repeat the test and if the readings for Vs and Va reach close to the expected results of 207 and 58 and then drop off? then that will mean it is one or both of the X & Y boards?

[tw2005]

Re: Samaung 43" Plasma PN43D450A2D will not power on

So I should disconnect X & Y boards and repeat the test and if the readings for Vs and Va reach close to the expected results of 207 and 58 and then drop off? then that will mean it is one or both of the X & Y boards?

yeah, I'll just have a dig and see if i have the guide and post it for the complete procedure. can't remember if it's just the power cables or if the ribbon from the logic too for disconnection.

[khi11]

Re: Samaung 43" Plasma PN43D450A2D will not power on

awesome, thanks for the responses and guidance! new area for me, so trying to learn and save some money!

[tw2005]

Re: Samaung 43" Plasma PN43D450A2D will not power on

guide

[khi11]

Re: Samaung 43" Plasma PN43D450A2D will not power on

Great - I'll run these tests later today and post my findings. Thanks for the support.

[tw2005]

Re: Samaung 43" Plasma PN43D450A2D will not power on

SUBJECT: Preventing the failure
or repeated failure of the X Ma
in board
SYMPTOM: No “power on” or “no picture”

[Shinju]

Re: Samaung 43" Plasma PN43D450A2D will not power on

X board failure on these is the Achilles heel of this line of Sammy plasma panels.

Some of the time when the x goes it takes the y board out with it.

[Shinju]

Re: Samaung 43" Plasma PN43D450A2D will not power on

Also when you get it back up and running update the firmware as soon as possible.

[khi11]

Re: Samaung 43" Plasma PN43D450A2D will not power on

So I powered up the TV again to monitor the logic board and during the initial start-up with the red Standby light and "clicking occurring, the green light on the logic board is blinking, but when the clicking stops, the green light goes out. It seemed like the green light alternated with short blinks and longer ones, but this only lasted for about 10 seconds. This TV was built in Feb 2011. I am afraid the guides may exceed my understanding of TV vocabulary.It sounded as though I need to add some jumper wires across certain connections to do further testing.

If there are some simple tests I can do determine which board(s) need replacing, I am up for that, but I could not tell which connections to disconnect, or "jump" and with or without power.

[khi11]

Re: Samaung 43" Plasma PN43D450A2D will not power on

I did some basic tests on the X-main and Y boards by simply unplugging them from the power supply and turning the TV on and watching the behaviour. The X-main appeared to be casing the failure mode. Bought a replacement X-main board from ShopJimmy.com and installed and upgraded the firmware - all appears good!

although the part supplier and this blog mention that upgrading the firmware can help prevent re-occurance of the failure. Samsung said the firmware upgrades only affect viewing optimization and NOT upgrading poses no risk to the TV. I asked Samsung as I have other Samsung models and have not checked for firmware updates.

Does upgrading the firmware actually reduce the possibility of failures such as this?

[tom66]

Re: Samaung 43" Plasma PN43D450A2D will not power on

I did some basic tests on the X-main and Y boards by simply unplugging them from the power supply and turning the TV on and watching the behaviour. The X-main appeared to be casing the failure mode. Bought a replacement X-main board from ShopJimmy.com and installed and upgraded the firmware - all appears good!

although the part supplier and this blog mention that upgrading the firmware can help prevent re-occurance of the failure. Samsung said the firmware upgrades only affect viewing optimization and NOT upgrading poses no risk to the TV. I asked Samsung as I have other Samsung models and have not checked for firmware updates.

Does upgrading the firmware actually reduce the possibility of failures such as this?

More Samsung bullshit... as expected, I guess, from a company like them.

There's even a tech bulletin out there which indicates this firmware DOES cause problems with the X-main, and updating it fixes the problem... of course, if they admitted it...
http://www.toms-service-manuals.com/...main&typekey=0

[Shinju]

Re: Samaung 43" Plasma PN43D450A2D will not power on

Its a variable voltage issue that was causing the Xmain to over voltage and die, in most cases it would take out the Ysus too and if you were super unfortunate the Ydrive and possible panel failure too.

At least this is what I was told.