un60j620dafxza - Samsung No Display Problem

[stylishconsultant]

Hi All,

Need help.

I have a samsung un60j620dafxza led tv. When I plug it in it has no display, no sounds, and no standby lights.

So I opened the tv and disconnected the power to the mainboard and the backlight powered up. This according to many people says that this is a mainboard
problem. I checked the voltage coming from the stb and I read 1.3 volts on pins 1,3,5 and 7 which are low volts instead of 13 volts which i think the lcd panel
might be drawing too much power from the power supply that it prevents the right voltage going to the mainboard. Does scenarios like this happen? I already
replaced the power supply twice. I even disconnected the LVDS going from the T-con to the mainboard and got no backlight. I also disconnected the cables of the Tcon connecting to the lcd panel and still no light. Based on these test I can somewhat conclude it is mainboard issue.

Here's the kicker, I disconnected the LED panel and re-connected the power supply to the main board. I checked the mainboard IR power up and standby
light turn on and the T-con board powers up! When I checked the display with a flashlight I can see an image and I can hear sound coming out from the TV!
I tried using the remote but the remote does not work which is odd. Even if the mainboard works this way is this a valid way to test it, does this mean if it powers the t-con board does it mean it is not defective? My concern is I do not see any tv-technician power the board this way they always test with the power connected to the led display power cable. I checked the voltages of power supply Pins 1,3,5,7 and it reads 13volts! Standby is 13 volts too and PS_ON is reading the right volts of 3.3 volts.

This makes me think that lcd panel might be defective. An tv repair told me it might be the lcd panel. But my gutts are telling me to order a mainboard to finally conclude if its a lcd panel defect because the led does indeed light when the mainboard is disconnected which according to many is enough to know. But when i applied the right voltage the motherboards somewhat works and powers the t-con board?

Any advice on what i should do? Has anyone experienced this mind boggling kind of scenario? I want to avoid buying a mainboard as possible because it somehow works with the right voltage. I think the lcd panel might be drawing too much voltage when it is connected to the power supply.

Below are my testing results:

Scenario 1: LED Panel disconnected.
The PS_ON reads 3.3vdc when turned on.
Pins 13v on pin 1,3,5,7
Power on LED Panel
Power on IR
Power on T-con board
Power on Standby led.
There is sound.
There is picture when light is shined on screen
T-con leds power up all 3 leds.

Scenario 2: LED Panel connected
The PS_ON reads .0015 volts
Pins 1.3v on pin 1,3,5,7
No Power on LED Panel
No Power on IR
No Power on Tcon
No Power on Standby led
No sound
No picture.

Scenario 2a: Disconnected LVDS
No power on Led Panel
No power on Tcon Board


Any advice would be greatly appreciated for curiosity's sake.

[nomoresonys]

If you have not, try it with one side of tcon to panel flat cable unhooked, check display, then do same with other side. I usually disconnect on tcon side, usually easier and less chance of cable end shorting out on any metal it might accidentally come in contact with.

[stylishconsultant]

Thanks for the reply. I already did that and there was no backlight.

[Diah]

please post complete photos of the whole back boards... include the LED BL socket on PSU to see if it direct LED or edge one.

[stylishconsultant]

Just to let you know i went a head an ordered a board. This concludes that the panel is broken for the sake of curiosity. Now i just need to sell the working parts off Ebay.

[EazyBone]

How does this conclude the panel is broken. You said you took a flashlight to the screen and saw a picture. That's a good sign that the panel IS working. I have this identical TV right now with the same problem actually. I just never ordered the board because it has diffuser caps floating around the tv.. didn't want to buy a board AND change LEDs.. so I was waiting for a broken TV to have a board