Samsung Plasma PN43E450A1F - No Picture / Pop Sound

[willis6732]

The customer of this TV Heard a pop sound before it went dead.

The VS and VA voltages turn on imediatly and then slowly die off.

I got a replacement Y-Board (Large board on the left) from aliexpress and still no luck

If tested all the IC chipson the board all the way on the left by running meter along the connectors and couldnt find any shorts there...

I think ive checked most the capacitors for shorts as well as most of the diodes and mosfet/transistors on the big boards.


https://photos.app.goo.gl/KDyLcgB38Bh699Zr6
https://photos.app.goo.gl/BB7y9AVgs51Ps4JH9
https://photos.app.goo.gl/mzjdQvFL96gdZRHy8
https://photos.app.goo.gl/1kpbuTgkZf9KzFUP6
https://photos.app.goo.gl/yfPeRQMro4KYKfKo8



Ps- If there a better way to host photos like on the badcaps server please let me know...

THanks
Kevin

[nomoresonys]

Re: Samsung Plasma PN43E450A1F - No Picture / Pop Sound

For pictures just hit the go advanced at the bottom then manage attachments.

[willis6732]

Re: Samsung Plasma PN43E450A1F - No Picture / Pop Sound

Thanks, Here are the pictures..

I forgot to mension a few things.

Once you hit the power button the green LED on the small board in the middle blinks one second on on second off.

Also the customer said that after the pop and no picture, the sound was still working.

[willis6732]

Re: Samsung Plasma PN43E450A1F - No Picture / Pop Sound

In the last set of pictures, On the main power board, there are two small blue ceramic capaictors that are getting hot. They are on both sides of double diode attached that heat sink.
I took the double diode out. Tested a short on the board and injected voltage... the transformer in the middle of picture got warm.

As for the two smallest boards, i havn't touched those at all. The big chips on each one are getting warm.


***SOMEHOW MY IMAGES BELOW GOT ROTATED>
PLEASE ROTATE THE REGULAR IMAGES BELOW CLOCKWISE 90DEG FOR THEM TO MATCH UP WITH THE THERMAL IMAGING PICS!!!

[Biruslapio]

Re: Samsung Plasma PN43E450A1F - No Picture / Pop Sound

If VS/VA go down slowly it means the psu is disarming because the mainboard signaled a shutdown, check the leftmost and rightmost boards(x-main and y-buffer) for shorts, and this board you bought too if there's anything wrong with it.

I recently repaired the Y-SUS of this TV, and there were a lot of possiblibly bad solder joints especially in the ceramic capacitors.

[willis6732]

Re: Samsung Plasma PN43E450A1F - No Picture / Pop Sound

If VS/VA go down slowly it means the psu is disarming because the mainboard signaled a shutdown, check the leftmost and rightmost boards(x-main and y-buffer) for shorts, and this board you bought too if there's anything wrong with it.

I recently repaired the Y-SUS of this TV, and there were a lot of possiblibly bad solder joints especially in the ceramic capacitors.

Dangit, found 3 bad IGBT chips on the Aliexpress Y-Sus board.

What is odd is that one of the chips that was shorted was also shorted on the original board..."FDG4536"

Could it be possible something shorted on the YSUS Buffer board is toasting the mosfets on the Ysus Board. Or it came that way?


Spent a bunch of time today double checking mosfets and solderjoints, cant seem to figure it out with meter...


Would it make sence to try and trace the VS and VA lines and try to figure out where exactly they go? Or perhaps inject voltage into the sus boards...



PICTURE IS JUST FOR REFERENCE OF BOARD NAMES. NOT WHAT IM WORKING ON

[Biruslapio]

Re: Samsung Plasma PN43E450A1F - No Picture / Pop Sound

https://www.badcaps.net/forum/showthread.php?t=117728
Read message #4, test your RJP, FGD and diodes, look for a blown ceramic capacitor, this could've happened to the original board.

IGBTs don't blow up for nothing unless they are fake, so something is bad, again, a shorted buffer or x-main can cause this, there are FGDs and diodes in the X board, these rarely fail.

[nomoresonys]

Re: Samsung Plasma PN43E450A1F - No Picture / Pop Sound

Yep check your scan driver/Y-buffer boards, bad ones can take out good Y-boards, testing there: https://www.youtube.com/watch?v=3Oq2MsU0XOQ https://www.youtube.com/watch?v=V6hxf9sARMY

[willis6732]

Re: Samsung Plasma PN43E450A1F - No Picture / Pop Sound

Thank you, I double checked the buffer board outputs (with it out of citcuit) and no shorts found their.

THe only odd thing i found on the buffer were the 4 bigger shorkey looking diodes test .012v in circuit. but test fine out of circuit .4v

Yep check your scan driver/Y-buffer boards, bad ones can take out good Y-boards, testing there: https://www.youtube.com/watch?v=3Oq2MsU0XOQ https://www.youtube.com/watch?v=V6hxf9sARMY

[willis6732]

Re: Samsung Plasma PN43E450A1F - No Picture / Pop Sound

https://www.badcaps.net/forum/showthread.php?t=117728
Read message #4, test your RJP, FGD and diodes, look for a blown ceramic capacitor, this could've happened to the original board.

IGBTs don't blow up for nothing unless they are fake, so something is bad, again, a shorted buffer or x-main can cause this, there are FGDs and diodes in the X board, these rarely fail.

"RJP63K2, FGD4536 and a SF10A400HD diode"

The SF10A400HD diodes seem bad.
one of them tests .5 one direction and .1 the other direction
One from the other board tests .6 one direction and .2 the other way.

The closet i found in my parts was a uf5408. Not sure if its close enough but I tried that but still no luck.

[nomoresonys]

Re: Samsung Plasma PN43E450A1F - No Picture / Pop Sound

Tested out of circuit right?

[willis6732]

Re: Samsung Plasma PN43E450A1F - No Picture / Pop Sound

Tested out of circuit right?

Yes, Thanks for the help. Prolly gunna let it go today

[Biruslapio]

Re: Samsung Plasma PN43E450A1F - No Picture / Pop Sound

unfortunate, but plasmas y boards are not easy to fix.

[nomoresonys]

Re: Samsung Plasma PN43E450A1F - No Picture / Pop Sound

I agree a real pain in the ass, I'm glad I never liked them.

[tongshadow]

Re: Samsung Plasma PN43E450A1F - No Picture / Pop Sound

Plasma boards are NOT meant to be serviced, and yes replaced. Add to the fact that it's IMPOSSIBLE to source original IGBTs/FETs nowadays, they're all fake and blow up. So replacing the boards is the most economical option.

I have a similar Samsung Plasma, if either YSUS or X-Board are bad, one will make the other fail. Always replace BOTH.