820-00840-a A1708 No Backlight

[tipoti]

hi,
i have 820-00840-a motherboard start on and apple logo but no backlight

i checked F8400, no problem. (pin 1-2 = 13 volt)

Also i checked D8410 (pin 1 = 13 voltage pin2 = 54 volt)

 

[TCRScircuit]

54 volts means there is no load on the circuit. Your issue is likely a bad screen. These models are common for flexgate. Have you tried a known good screen yet?