Samsung UE58MU6125K flashing standby led only

[london-freddie]

Just picked this tv up very very very inexpensive and just over one year old, I will keep it for myself once working
Been told switched on one morning and it was dead only the red standby led flashing when remote buttons pressed
Got it home, removed back cover, that was interesting with no screws holding it.
First check was output to leds when powering on, good but tv not powering up.
Removed cable from power board to mainboard, screen panel lit up, so I assume led's are ok
Checked all voltages on powerboard and all seem to be ok, maybe I am wrong.
1/ 2.65v
2/ 2.76v
3/ 12.95v
4/ 3.62v
5/ 12.95v
6/ 3.14v
7/ 12.95v
8/ 3.95v
9/ 12.95
10/11/12 all 0v

powerboard BN44-00808E
Mainboard BN94-12640G
If these power board readings are ok will I be correct in assuming this is a mainboard problem
Any help with this appreciated, thanks
Will post pics in a few minutes

[london-freddie]

Re: Samsung UE58MU6125K flashing standby led only

Pics of boards

[Diah]

Re: Samsung UE58MU6125K flashing standby led only

MU series had problem with following

1- eeprom
2-wlan module
3- LCD & T-con

put it in stand by. and check PSU J807 how much V you have, as listed it should 7.5

[london-freddie]

Re: Samsung UE58MU6125K flashing standby led only

Hi thanks for that just checked j807 getting 12.9v, pressing power button does not seem to make any difference to this 12.9, can not get 7.5v
removed wlan still same

[Diah]

Re: Samsung UE58MU6125K flashing standby led only

the measurement should be done within the set at Standby. RED LED STABLE ON.. no flashing

[london-freddie]

Re: Samsung UE58MU6125K flashing standby led only

Yes I think the set is in standby the red led is on and not flashing, I have 12.9v
if I press power button led flashes a couple of times then goes back to stable on, the 12.9v does not seem to change whilst the led flashes, it seems to be at 12.9v all the time there is power to the powerboard, If that makes sense

[budm]

Re: Samsung UE58MU6125K flashing standby led only

8/ 3.95v
That PS-ON pin 8 does not change state at all and stick at 3.95V when toggle power switch on and off? If it stays at 3.95V then you will have 12V instead of 7V (in standby) because it is stuck on.

[london-freddie]

Re: Samsung UE58MU6125K flashing standby led only

Hi budm pin 8 @ 3.95v does drop to zero volts when power button pressed but back to 3.95 when power button is released. J807 never gets the 7.5v

[london-freddie]

Re: Samsung UE58MU6125K flashing standby led only

just tried J807 again, 12.9v if I press and hold the power button, just for a split second J807 drops to 9.9v and then immediately goes back to 12.9v with the power button still pressed

[london-freddie]

Re: Samsung UE58MU6125K flashing standby led only

Any first ideas on this main board, power board or something else ...?...?

[budm]

Re: Samsung UE58MU6125K flashing standby led only

At this point it looks like the power supply/LED driver boards are OK.
Did you try disconnecting the WIFI module to see what happen?
Disconnecting T-CON to see what happen?

[london-freddie]

Re: Samsung UE58MU6125K flashing standby led only

Disconnecting WIFI module and T-CON board makes no difference

[Diah]

Re: Samsung UE58MU6125K flashing standby led only

1- put the TV in stand by mode, plug any DVD or blue ray device with HDMI at ARC function input then turn on the device you connected to the TV. check how the TV response
2- take out the black cover of the cpu, and freeze the eeprom and all component around then plug it in wall socket.

[london-freddie]

Re: Samsung UE58MU6125K flashing standby led only

Hi As per Diah Froze eeprom and surrounding area, still no power up
No change when HDMI input made

[london-freddie]

Re: Samsung UE58MU6125K flashing standby led only

CPU on mainboard does get warm, so getting some power there

[Diah]

Re: Samsung UE58MU6125K flashing standby led only

inspect the MB all inputs pin if there are short

[london-freddie]

Re: Samsung UE58MU6125K flashing standby led only

Hope I am not wasting money but have just taken the plunge and ordered a replacement mainboard, listed as brand new from a seller in Spain, only one that I could find same as that currently fitted to the set, Now a long wait for the postman

[Diah]

Re: Samsung UE58MU6125K flashing standby led only

let wait and see.. i personality had very bad experiences with Spain eBay seller in general..

[london-freddie]

Re: Samsung UE58MU6125K flashing standby led only

let's hope it's not same seller

[Diah]

Re: Samsung UE58MU6125K flashing standby led only

meanwhile now the road open to you to try crazy ways.. but some time it help

take your MB with out black cover of the CPU to the kitchen, heat your oven to maximum with out air flow, put the MB there for 10 minute and then turn off the oven and open the door, to let it cooling down with out touching the MB... test it