Power board problems bn44 00859a

[mrmonza]

Hello. I have a samsung ue55ju6875u that hade led backlight problem and the cause was a glitchy conector to the led feedstrip.

The problem now is that the wire pin 1 on the led connector broke lose an shorted against the chassie and now the tv is dead, no red light when plugging in the power cord before the short the relay clicked and it was a red light for a few seconds then it blinked 5 times.

The power board is an bn44 00859a can anyone point me in the right direction what to check to solve the problem or maby someone have an electrical diagram for a bn44 00859a.

best regards Emil

[nomoresonys]

Did you check the fuse? it's there by where the power cord plugs in.

[mrmonza]

Yes, l have located 2 fuses both are ok.

[lotas]

Check on which channel the wire is shorted to ch1 or ch2 and measure the voltage that appears on the high-voltage capacitors when switching to operating mode.

[mrmonza]

Ch1 both cap reading 1.145v and ch2 cap both reading 0,795v when powering on.

[lotas]

Check to see if there is a short circuit between the pins of these components.

[mrmonza]

My multimeter beeps in continuity mode between gate drain and sorce on the mosfet in pic1 and between drain and sorce on the mosfet in pic 2, i will remove dem to test them.

[mrmonza]

The 2 mosfet was faulty and when i flipped the board i found this SLC5012M it looks like it have been really hot and broken, is there a way to test it?

[nomoresonys]

Appears to have a hole in it, I would replace that also and check all the components in that area on that circuit.

[lotas]

The 2 mosfet was faulty and when i flipped the board i found this SLC5012M it looks like it have been really hot and broken, is there a way to test it?

Due to the breakdown of the mosfets, the backlight driver also suffered, just replace it with a new one.

[mrmonza]

Thanks for all tips so far, i will order new components and give you an update when the broken components are changed out.

[lotas]

You just need to carefully check the remaining components, diodes, zener diodes, transistors, mosfets, resistors..., otherwise when installing new components they can burn out again, everything is interconnected.

[Davi.p]

you have to remove the holed chip and re test the mosfets.. one of the smd mofets surely dead..