Samsung UE70TU6905 BACKLIGHTS AND SOUND ON NO PICTURES BUT SCREEN NOT DARK

[lotas]

i do not understand why there is 180v and 190v on the cold side of the power supply

This is power for backlighting, it cannot be 12v.

[bohaboha]

There is nothing complicated here, they are here, install a jumper between them and disconnect the U-shaped cables on the panel strips one by one...

Doing this test suggested by apokalipto to activate pmic voltages shorting trdy1&3 test points did not change anything in tv behaviour always stack on STBY and nothing happens on screen
here some pics mainboard without heatsink i do not find datasheet of this SDP19405

[Diah]

stack on STBY , this is different status as the Title you stared the threat.... what did you done wrong to make the set didn't start??

[bohaboha]

[QUOTE=Diah;n3547547]stack on STBY , this is different status as the Title you stared the threat.... what did you done wrong to make the set didn't start??[/QUOTE

nothing special just try t take away the black heatsink that was a bit hard to do

[Diah]

nothing special just try t take away the black heatsink that was a bit hard to do

if this was only the dry pasta when you try to remove heatsink caused BGA on the SoC. , no other choice now just refllow , apply weight load on the Soc at the middle and use yours heat gun over all rand and middle. good luck

[bohaboha]

if this was only the dry pasta when you try to remove heatsink caused BGA on the SoC. , no other choice now just refllow , apply weight load on the Soc at the middle and use yours heat gun over all rand and middle. good luck

yes i it is .it hapen that i have this IRDA SMD And BGA Rework Station T-862++ i am thinking to use to just reflow the chip but i believe i will need a good liquid flux that i do not have it now to help the situation if you know wish one i should take ? i have already solder paste 01 but i think a liquid one will be better

[bohaboha]

Hi again all lovely people. Diah now I have found a 58 Inches as you recommended that Mainboard with Even numbers would fits it is on the way hopefully already on Monday.
Have already tried a 65 Inches as I already have it everything got started except the picture plus the STB light was on all the time and the tv did not react for the remote so I hope that wil work with this 58 would work

[bohaboha]

Hello again to all of you who helped in this thread and the rest of you who hope to be able to contribute with some suggestions.
Now I have received a replacement MainBoard for this model a BN 41-02751B-000 number on the circuit and BN94-15566L ON THE STICKER
it's for a 58 inches min is 70 inches was told by Diah that any even mainboard with even numbers would fit.
Now I don't dare to try the table on my set because I'm a little suspicious about an uneven current coming from Power Supply to Mainboard

on this PS there is no full specification of the connector CNM801
the upper row the lower row of the socket
1)GND 2) ANA_DIM :2.54 loop1.754V t
3) A13V 4) N C
5) A13V 6) PWM_BLU :3.35V
7) A13V 8) POWER_ON :4.584V
9) A13V 10) GND
11) GND 12) GND
the 13V is present om the upper row 12.93V
For the STB and something named ON in the front of the CNM801 referring to 3 Jumper there must be 12.3V and 12.35V i do have 12.93V on those jumper

the question now is why ANA_DIM is behaving that way loop from 2.5V i to 1.754
the PSU seems to be ok because when i disconnect the Mainboard the Backlight is on but still the Mainboard must have the right voltage from the PSU and that 2.4v is enigmatic

[Diah]

Hello again to all of you who helped in this thread and the rest of you who hope to be able to contribute with some suggestions.
Now I have received a replacement MainBoard for this model a BN 41-02751B-000 number on the circuit and BN94-15566L ON THE STICKER
it's for a 58 inches min is 70 inches was told by Diah that any even mainboard with even numbers would fit.
Now I don't dare to try the table on my set because I'm a little suspicious about an uneven current coming from Power Supply to Mainboard

on this PS there is no full specification of the connector CNM801
the upper row the lower row of the socket
1)GND 2) ANA_DIM :2.54 loop1.754V t
3) A13V 4) N C
5) A13V 6) PWM_BLU :3.35V
7) A13V 8) POWER_ON :4.584V
9) A13V 10) GND
11) GND 12) GND
the 13V is present om the upper row 12.93V
For the STB and something named ON in the front of the CNM801 referring to 3 Jumper there must be 12.3V and 12.35V i do have 12.93V on those jumper

the question now is why ANA_DIM is behaving that way loop from 2.5V i to 1.754
the PSU seems to be ok because when i disconnect the Mainboard the Backlight is on but still the Mainboard must have the right voltage from the PSU and that 2.4v is enigmatic

what.. hahahah when i said or write this. post #36 was talking on even Panels how shit they are LOL

[bohaboha]

what.. hahahah when i said or write this. post #36 was talking on even Panels how shit they are LOL

Yes you did . but i have try repair it for a mother of 2 kids that are without tv now and i feel very sorry for them . now as you said i took this board 58 inches but i want to fix this floating voltage on power supply before i connect the new board.

[Diah]

Yes you did . but i have try repair it for a mother of 2 kids that are without tv now and i feel very sorry for them . now as you said i took this board 58 inches but i want to fix this floating voltage on power supply before i connect the new board.

i would love to link me to my post..
any way.. DIM over all brands are VCC control BL brightness supplied by MB... so how it come you have it and MB disconnected as you said ?

[bohaboha]

i would love to link me to my post..
any way.. DIM over all brands are VCC control BL brightness supplied by MB... so how it come you have it and MB disconnected as you said ?

I do not really know if it is ANA_DIM but as i said in post 88 "on this PS there is no full value specification of the connector CNM801"
and the diagram on the board is a same as in my post 88 so i suppose it is it . have to us microscope to read it. here some pictures of the legend .
When MainBoard connected only the 12V is present no backlight and all the low voltage 2.5V ,3.3V and 4.5V disappears

[Diah]

you mean no print charts of the socket pins on PSU..! check the downside too

[bohaboha]

you mean no print charts of the socket pins on PSU..! check the downside too

yes the print chart it needs a microscope to se it . Diah do you think is it possible that the power supply can destroy the MainBoard with that looping voltage on that pin ? because i want to try the new board

[bohaboha]

Here some pics of the chart

[Diah]

remove pin2 from the socket and connect the replacement MB to PSU, be sure to compare the socket on MB are same component and circuit as the original,
main function you have A13V will be round 7.5V at standby and then go high after MB send Power_on and the BL to turn on when MB send BLU_ON. , if you got screen and optic port lit red we can deal with ANA_DIM

[bohaboha]

remove pin2 from the socket and connect the replacement MB to PSU, be sure to compare the socket on MB are same component and circuit as the original,
main function you have A13V will be round 7.5V at standby and then go high after MB send Power_on and the BL to turn on when MB send BLU_ON. , if you got screen and optic port lit red we can deal with ANA_DIM

yes both of them are on but no pictures and TV not reacting for RC .pin 2 is removed

[Diah]

same result as original MB.. right? optic port lit red?
install the jumper of feed back points on the MB, and disconnect U ribbon from half one by one
the response of RC could be the front IR on TV had different out put as yours.. you can disconnect it also if wifi disconnect it too

[bohaboha]

same result as original MB.. right? optic port lit red?
install the jumper of feed back points on the MB, and disconnect U ribbon from half one by one
the response of RC could be the front IR on TV had different out put as yours.. you can disconnect it also if wifi disconnect it too

not really same result on the original i did have sound and the RC working in the beginning then something happened .yes the optic lit red. ok looking to the Tv the left U Ribbon unhooked the result is the screen is same as in post 97. the U Ribbon unhooked from the right side always looking to the screen big difference first it shows Logon Smart TV and some apps over 3 quarter of the screen but just for 3Seconds and then start looping but no picture this time and the standby lit 3 times 2 flashes

[Diah]

i wrote you need to install the jumper on 2 feedback points on mainboards ... did you ?