Failing Samsung UE55ES8005U power supply

[anders.ovreseth]

My Samsung TV, UE55ES8005U, has some problems. I have been checking for signs of problems and found that one pin on the main cable between the power supply board and the main logic board / controller is brown and looks burnt. I have also observed that the TV never quite shuts completely down when pressing the power button; backlight turns off but the light in the "Samsung" logo is always on until I disconnect power.

Because of this I am suspecting either a faulty cable or faulty power supply board. Can someone help me with further diagnostics of what to do? The cable looks good on the other end connected to the main logic board.

Pictures attached.

 

[betwixt]

The problem is likely to be that burned connector. There is a table of the pin connections printed on the board beside it but the picture isn't sharp enough to read it. Can you tell us what it says or send a clearer photograph please.

Brian.

 

[anders.ovreseth]

Many thanks for your reply. I am posting a new picture with the pinout of the connector.

 

[KlausST]

Hi,

backlight turns off but the light in the "Samsung" logo is always on

The power supply is on standby. Power is still available for the IR receiver, so you can POWER ON the TV with your remote control.

**********
The burnt pin is a problem. Both sides need to be cleaned carefully and maybe mechanically adjusted.
Check temperature after power ON .. for at least half an hour. Do the same in STAND BY.

**********
The most frequent problem with SAMSUMG power supplies are expired electrolytics capacitors. When they get old the voltage regulation gets out of control. Maybe causing overvoltage and overcurrent. This could be the problem that caused the pin to get burnt.

Klaus

 

[anders.ovreseth]

Many thanks for you reply, much appreciated. In the past the light in the Samsung logo was alway turned off in standby, so there is a change in behaviour.

Could dust also has been the root cause / cause of problems with voltage control? There was substantial amounts of dust under the back cover when I first disassembled the unit.

I have inspected all of the capacitors visually and they seem ok, even though I know it is not always visible when they are struggeling.

Would it be advisable to source a new power supply board and maybe a new cable? In case yes, what are good ways to order this type of parts?

 

[betwixt]

Getting hold of a new cable might be surprisingly expensive. I think my strategy would be to solder a wire link from the solder pads on the connector at each end of that wire so it is 'bypassed'. That will prove if the connector is the only problem. If it fixes everything you can either leave the wire in place or seek a new cable assembly and socket. Change the socket as well because the heat will have changed it's metallic properties and could make it overheat again.

Brian.

 

[Externet]

Try Settings ---> System ---> expert settings ---> Light effect? ---> OFF
Or, go to Menu ---> Support ---> Self diagnosis. Explore if clarifies something.
Perhaps you want to try 'Reset'

My TV shows option of turning front panel indicator on/off.

 

[anders.ovreseth]

Hi,

The power supply is on standby. Power is still available for the IR receiver, so you can POWER ON the TV with your remote control.

**********
The burnt pin is a problem. Both sides need to be cleaned carefully and maybe mechanically adjusted.
Check temperature after power ON .. for at least half an hour. Do the same in STAND BY.

**********
The most frequent problem with SAMSUMG power supplies are expired electrolytics capacitors. When they get old the voltage regulation gets out of control. Maybe causing overvoltage and overcurrent. This could be the problem that caused the pin to get burnt.

Klaus

I checked the heat both for the power supply board and the main logic board after having the TV on for about an hour. The temp was about 40 degrees C on the back of the TV (the TV was fully assembled). Perhaps a bit hotter on the main logic board than the power supply board. When the TV is in stand-by the temperature is the same as room temperature.

 

[anders.ovreseth]

Getting hold of a new cable might be surprisingly expensive. I think my strategy would be to solder a wire link from the solder pads on the connector at each end of that wire so it is 'bypassed'. That will prove if the connector is the only problem. If it fixes everything you can either leave the wire in place or seek a new cable assembly and socket. Change the socket as well because the heat will have changed it's metallic properties and could make it overheat again.

Brian.

Thanks , this is a good suggestion. After cleaning the connector, reseating it as well as remove all dust inside the TV it has been stable for many days. I am aware that the capacitors might blow on me any day so I also ordered a new power supply board so I have it at hand.

I am also looking for the cable connecting the power supply board and the main logic board, but I have so far not been able to find a source for it. Hopefully the cable is ok, I am considering cutting back the wire that had overheat problems a few cm and soldering it back to the connector.

 

[KlausST]

The temp was about 40 degrees C on the back of the TV

This gives no indication of pin temperature...

 

[anders.ovreseth]

I do not have a multimeter that can measure temperature like some of the fancy Fluke ones can. So I don't really have a good method for measuring the temp on the pin itself.

 

[KlausST]

Hi,

A finger should do the job.
Expect high voltage and high temperature, thus be careful.

Klaus