UA55KU6000WXXY Samsung Mainboard need identify part

[sidds]

Have a UA55KU6000WXXY Samsung Mainboard (BN94-10801A, other generic part number: BN41-02528A) which is not giving the voltage at the Test point after the 8 pin MOSFET which is fed by the IC401_UT. Can anyone identify that part?

[diif]

Re: UA55KU6000WXXY Samsung Mainboard need identify part

Its a BM81249MWW DC/DC converter.

[sidds]

Re: UA55KU6000WXXY Samsung Mainboard need identify part

Its a BM81249MWW DC/DC converter.

Thank you diif for the awesome info. Any reliable supplier shipping at reasonable cost to Australia? I need just 2 or 3 units. Got some outrageous quotes of AUD 20 or more for a single unit. Ebay stores are shipping entire motherboards for that amount. Thinking of buying a board and using it for parts to fix the current bad one. Any thoughts would be welcomed. Cheers

[diif]

Re: UA55KU6000WXXY Samsung Mainboard need identify part

They do seem more expensive than usual.
If you can find a cheap working replacement board with the same part and have the skills/tools to remove it without damage that's the route I'd take.

[sidds]

Re: UA55KU6000WXXY Samsung Mainboard need identify part

Thank you diif. Are any service manuals available for this mainboard? Google search did not yield anything. Cheers.

[diif]

Re: UA55KU6000WXXY Samsung Mainboard need identify part

Doubtful. The service manuals are designed for their engineers to diagnose and swap boards, not to help us with component level repair.

[sidds]

Re: UA55KU6000WXXY Samsung Mainboard need identify part

Ordered a board BN41-02528A to harvest parts from ebay UK.
Will keep an eye on gumtree as well.
Hopefully I'll have some news to share once the board arrives.
Cheers

[sidds]

Re: UA55KU6000WXXY Samsung Mainboard need identify part

Hi ,
Can I bypass that BM81249MWW DC-to-DC converter IC and power up the MOSFET by grounding the gate ( pin 4) of the 8 pin MOSFET?
Cheers

[sidds]

Re: UA55KU6000WXXY Samsung Mainboard need identify part

Bad news. Got the main board from ebay, but it is continuously boot looping. Cannot get any voltage at the test point shown in the first pic either. Asked ebay seller to help or refund. any other avenues i can follow? Your help is very much appreciated. Cannot get hold of the original main board either.

[sidds]

Re: UA55KU6000WXXY Samsung Mainboard need identify part

Hi,
I need help to diagnose the problem either with mainboard or with the Panel ( suspected to be Cracked). The original mainboard boots up, get the backlights ON and the boot-up sound is also there, but the HV_IN_12V is at 0V.
The replacement board from ebay is boot-looping and I can not measure any realistic voltages on any test points.
I'll post some clear pictures of the panel when ON and the test point pictures as soon as I get the time to open it up again. For ref, I have one in the 1st post.
In the meanwhile, any help or method to systematically check the Panel or mainboard would be very much appreciated.

Kind Regards,