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

[bohaboha]

Hi again here the pictures of the 3 Mainboards they are almost identical only the 65 inches which differs with the others with socket on the upper left corner and it is active but probably they are not compatible as the 58 inches dealt with in this thread does not correspond to this Screen and neither for the remote control maybe it needs to be reprogrammed (region issue )

[bohaboha]

Yes, there were never any problems with them, here in the photo there are control points, check the resistance with a multimeter between them (between 1 and 2, between 1 and 3,...., between 2 and 3, between 2 and 4, and so on) and between the ground, there should not be low resistance.

Hi lotas am waiting your response about my answer very curious how the test should be done thank you

[bohaboha]

zoom in the photo.. you will see 2 pins are like connected together,, u need to clean them.... also remove the jumpers totally u don't need it any more.... work on the panel , masking or scrap it

no Diah it is not a short some particule on it it is clean now and it looks ok. instead of scraping the set why not move some component from 58 inches board to the 70 inches like the DC to DC chip and try the old board this is if it is not possible to use this one on the 70 inches .
and i do have a board for 65 inches that have only one LVDS to the Screen it looks identical to the 70 inches
i ll post some pictures of them all to se the differences

[Diah]

zoom in the photo.. you will see 2 pins are like connected together,, u need to clean them.... also remove the jumpers totally u don't need it any more.... work on the panel , masking or scrap it

[bohaboha]

you have panel issue ....... check the LVDS socket ( red circle ) if there short contact !.. after you clear this, do only masking on the blue marked area..

the test is between those 2 red point or to ground ?

[bohaboha]

keep it in this test mode... just disconnect half screen a time

Left U ribbon disconnected loop with lite Screen then black every start is with lite screen.
same with the right U ribbon disconnected
but with only the middle connected without the left and right side that part is steady no more loop you can se the picture in post 104

[Diah]

you have panel issue ....... check the LVDS socket ( red circle ) if there short contact !.. after you clear this, do only masking on the blue marked area..

[Diah]

keep it in this test mode... just disconnect half screen a time

[bohaboha]

MB with jumpers, connected only to power boards and screen.... no other sockets of wifi or front LED indicator IR FB

resolt : The set starts with backlight on Screen black then loop the screen get a bit clear like if it wants to clunch then black and so on

[Diah]

MB with jumpers, connected only to power boards and screen.... no other sockets of wifi or front LED indicator IR FB

[bohaboha]

as i know TU even size MB have only one LVDS, the odd have 2.
however i would like you start the TV with out any socket of WIFI and front IR, let us testing in such condition only.. the jumpers must be in place

Sorry Diah i do not understand what do you mean with "start the TV with out any socket of WIFI and front IR," take away the wifi connection and the jumper it is ok but the other ????

[Diah]

as i know TU even size MB have only one LVDS, the odd have 2.
however i would like you start the TV with out any socket of WIFI and front IR, let us testing in such condition only.. the jumpers must be in place

[bohaboha]

then you have different between the 2 boards function.

somehow it have to be some difference it is a board for 58inch and mine is a 70 inches as you know but i follow your recommendations you said any even number should work i know it is not a guaranty but do you think it will work ?.

[Diah]

no i dit not solder anything on the board and the jumper i desoldered one side of it but leave it there for further test if it needs.
is the pictures good for your request?

then you have different between the 2 boards function.

[bohaboha]

did you soldered out part from the original boards close to the LAN port? its look huge short caused at it which effected the IR boards..
by the way yours jumpers don't let with chassis in contact

no i dit not solder anything on the board and the jumper i desoldered one side of it but leave it there for further test if it needs.
is the pictures good for your request?

[Diah]

Jumpers should solder in 90° of points not from side.

[Diah]

did you soldered out part from the original boards close to the LAN port? its look huge short caused at it which effected the IR boards..
by the way yours jumpers don't let with chassis in contact

[bohaboha]

post photos with remark on yours original MB and the replacement only on LVDS socket and front IR-LED indicator socket and WIFI socket

Hi Diah here some pictures of both boards the native one has hand written notes on it
the first row of pictures is the old one

[Diah]

post photos with remark on yours original MB and the replacement only on LVDS socket and front IR-LED indicator socket and WIFI socket

[bohaboha]

Yes, there were never any problems with them, here in the photo there are control points, check the resistance with a multimeter between them (between 1 and 2, between 1 and 3,...., between 2 and 3, between 2 and 4, and so on) and between the ground, there should not be low resistance.

Hi Lotas if I have understood correctly i should measure the points between them, that is, 1 against 2,3,4 to number 14
Then all the points in the same way.
test the points to the GND from left to right:
266.5k ohms most points except 2 which is 3325.6k ohms
The points in between are quite mixed very hard to report everything here from: 09895mH, 1.755m ohms this for the first point against the others.
If you want me to report everything I'll find to record values without typing one by one and then write here
Or maybe a few points are enough. thank you