Toshiba satellite L55Dt-B5175SM PSKUAU DA0BL0MB8F0 REV F

Hi, I have
DA0BL0MB8F0 rev F but it has backlight problem. Is there any way somebody without schematic to help how to resolve the issue? I know it used to be Nuvoton the backlight controller but in old models so i dont know if its still the same on new ones

 

Backlight is not a problem bios.

 

Check 3.3v voltage led have if not check led connector pin 5 and pin 6 show(3.3v) have or not?

 

Yes 5 and 6 pins have 3.3 volt. i am wondering which pins control the backlight voltage so i can bypass it and wire another 3.3 voltage to give the required voltage for the backlight to come on. it use npce985la0dx which control the backlight voltage i believe but there should be some extra controller before it reach the LCD connector. The connector is 30 pins so i couldnt find any similar toshiba diagram which will have npce985la0dx as power controller and lcd connector to be 30 pins instead of 40. Any more ideas would be helpful

 

Its AMD but what do you want me to check with GPU and which lvds IC you mean? Be more specific if you want to help or know where to look...

 

The thing is that mainboard lcvds connector is 30 pins but the lcd cable connect to screen with 40 pins so if we knew on the screen pin which of the 40 pins the backlight power pin is then i could wire it from there or check where it beeps on the board

 

Check near connector (fuse) and 0 ohm resistor.

 

So after the backlight came by itself the keyboard stop responding so i believe the nuvoton was the issue from the beginning . I replaced the nuvoton IC and all worked fine