820 3437 backlight issue

[Jay]

hey folks,

Got a 820 3437 that came in for no backlight. Replaced the backlight driver and now the backlight works for a second after the chime, then turns off. Any ideas on where I should start looking for the issue here? The driver works, backlight works but something is turning it off. This issue is not making sense to me so don't know where to start

Any help appreciated

 

[2informaticos]

Image still present, only backlight goes off?
Did you try known good LCD assembly?

Post BKL_EN/PWM levels; also diode mode to ground at all return resistors.
Be sure to have good trace from A5/U7701 to K/D7701.

Try PRAM reset few times, just in case...