Samsung un55h6203afxza us01 no backlight

[crdz66]

Hello.

I need you value opinion on this case.
This tv show sound but not backlight or video.
The original ps show really on led drivers connector high value on m1+ but almost 0v on m2+,m3+,m4+ and m5+

that make to take the decision replace not only ps if not the all kit include ps, main board and t-con board.

But still show the same symptoms.
No backlight, no video but sound ok.
The connections on ms1 still remain on 280v-320v fluctuating and another m+ remain 0v.

What i doing wrong or new ps is bad?
Thanks

[dskall]

Re: Samsung un55h6203afxza us01 no backlight

Need pictures and voltages

[budm]

Re: Samsung un55h6203afxza us01 no backlight

Sounds like open circuit in the LED string but we cannot really tell much until we see good clear hi res pictures of the whole back side of the TV and the boards.

[crdz66]

Re: Samsung un55h6203afxza us01 no backlight

Ok.
Connector CNM803 (Main-PS)
1,3,5,7 are 12,7v
9 is 0v
2. 2.3v
4. 3.2
6. 4.4v
8,10 gnd

connector cnl802 led driver (connect to led strings)
m1+ - 280-320v floating
m2+, m3+, m4+, m5+ = 0-7v floating



connector cnl802 led driver (w/o connected)
m1+ - 280-320v floating
m2+, m3+, m4+, m5+ = 0-.3v floating

Additional comments.
As soon turn on the tv, after 3 secs, you can see a quick light from backlight but less a second. The light is really poor not intense.

[budm]

Re: Samsung un55h6203afxza us01 no backlight

http://www.shopjimmy.com/samsung-bn4...led-board.htm#

BN44-00774A.
You have open circuit in the LED string, the LEDs are connected in series to form one long string.
The M1+ is the Anode of the first LED in the string and the M5- is the Cathode of the last LED in the string.
Pictures provided by shopjimmy

[crdz66]

Re: Samsung un55h6203afxza us01 no backlight

dump question.
Do I need replace power supply board?

[Andrew F. Ali]

Re: Samsung un55h6203afxza us01 no backlight

No. You need to strip your panel down to the LED backlights and replace any LEDs not working.

[crdz66]

Re: Samsung un55h6203afxza us01 no backlight

But, even if led connector is not connected I still have the same readings.
I understand when is connected can have open circuit because the low readings, but what happend when is not connected???. How can open circuit is detected?

[dick_barton]

Re: Samsung un55h6203afxza us01 no backlight

When a led(s) is open circuit no current flows and the Led driver chip detects the lack of current flowing so is the same as not plugging in the leds.

[crdz66]

Re: Samsung un55h6203afxza us01 no backlight

Thanks.

[Andrew F. Ali]

Re: Samsung un55h6203afxza us01 no backlight

When a led(s) is open circuit no current flows and the Led driver chip detects the lack of current flowing so is the same as not plugging in the leds.

+100