Samsung UE40EH5000K No Power

[jasonr2000]

hi guys I have the above mentioned TV and it appears completely dead.


no power light nothing


I have removed the mainboard to see if the back lights would fire up incase it was a mainboard issue

and its still dead ?


does this link to a bad PSU ?


thanks for any help

Jason

[jasonr2000]

Re: Samsung UE40EH5000K No Power

here are photo's of the PSU guys

[dskall]

Re: Samsung UE40EH5000K No Power

Need voltages from connector that goes from power supply board to main board. Will need pin#- PIN DESCRIPTION -Pin voltage in standby-Pin voltage when pushing power button and picture of connector on power supply board.
Format:
Pin# - Pin Description - Pin Voltage standby - Pin voltage power on
1 - XXXXXXX - XXv - XXXv
2 - XXXXXXX - XXXv - XXXv
3 - XXXXXXX - XXXv - XXXv
4 - etc.

[jasonr2000]

Re: Samsung UE40EH5000K No Power

Hi there.


Thanks for the reply there is no output at all i have done some further testing and the fuse FP8015 T5.0AH 250V


Has blown

So no power at all on any connector

Thanks

[dskall]

Re: Samsung UE40EH5000K No Power

Well I would say a bad power board

[jasonr2000]

Re: Samsung UE40EH5000K No Power

Thanks for the reply im going to do some more testing and if no go ill just get a replacement power supply

[dskall]

Re: Samsung UE40EH5000K No Power

Try checking bridge rectifier. Thought you just wanted to know what board is bad.

[jasonr2000]

Re: Samsung UE40EH5000K No Power

Anything else to check ?

[budm]

Re: Samsung UE40EH5000K No Power

Anything else to check ?

Check all the Devices that are mounted on the heatsink in the primary side of the circuit for shorts.

[jasonr2000]

Re: Samsung UE40EH5000K No Power

Thanks Budm will post back what i find

[thoma]

Re: Samsung UE40EH5000K No Power

https://www.electronica-pt.com/esque...-00496b-29976/

[jasonr2000]

Re: Samsung UE40EH5000K No Power

ive discovered a few parts are bad on the PSU


DM855C
DM857C
DM853C
DM851C

have no continuity at all


and the main input fuse

is there any point repairing them ?


or should I just replace the board ?

thanks

[dskall]

Re: Samsung UE40EH5000K No Power

Seems strange you have blown fuse and open diodes

[jasonr2000]

Re: Samsung UE40EH5000K No Power

I agree with you it just went dead for no reason,


ive checked most of the others and they test out ok

whats the worst that would happen if I replace the fuse with the same one and replace the diodes ?

the diodes that have gone are on the backlight circuit


ive noticed that

Jason

[R_J]

Re: Samsung UE40EH5000K No Power

How are you measuring the diodes? are you using the diode test mode on the meter or just checking their resistance?
If the diodes are indeed open, that will not blow the fuse.

[budm]

Re: Samsung UE40EH5000K No Power

https://www.badcaps.net/forum/attach...7&d=1513635033
So the MOSFET mounted on the heatsink where the bridge rectifier is also mounted tested OK?

[jasonr2000]

Re: Samsung UE40EH5000K No Power

hi guys ive tested the diodes for continuity


all the other diodes check out ok

the mosfet doesn't appear to be shorted guys,


the bridge rectifier is also ok

thanks for all the help so far,



im having issues finding a PSU for this tv the part number of the PSU is BN44-00666B


can I use the Revision BN44-00666A ?


all the pin outs are the same

[diif]

Re: Samsung UE40EH5000K No Power

Diodes don't show continuity. Test in diode mode, put the leads on one way then the other.
How are you testing the other components ?
As for repairing than replacing, it's uncommon to find a board cheaper than the components for a repair, it just depends on your skills/tools.

[jasonr2000]

Re: Samsung UE40EH5000K No Power

Hi guys


Sorry ive not been in touch sooner.

Happy new year to you all.


Well anyway the mosfet is shorted to ground as ive discovered that by testing it with a multimeter.

Ive got a replacement mosfet but its slightly less on the spec

The original one is a 60R580P
And the replacement one is a 13N50C

Do u think it would be ok for testing purposes as im still learning all this.


Thanks

[dskall]

Re: Samsung UE40EH5000K No Power

Underspecd component may work for testing but will not last.