(347) 552-2258 help@rossmanngroup.com

820-00165 very dim LCD

2informaticos

2informaticos

Administrator
Staff member
"bkl_pwm is 0volts"
Remove R7704 and run a wire from R7715/31 to C7704.
If you get backlight, do PRAM reset 2-3 times and rebuild original circuit; test again the backlight then.
 
Outofwhack

Outofwhack

Member
Backlight came on bright after jumping.
I replaced resistor and cap but I am unable to verify continuity of track to cpu as there is no accessible test point at cpu end.
bkl_pwm remains at 0v and image very dim = same as before.

I have to admit also I am currently not getting a light on the charger lead although I get a chime and its starts to boot.
 
Outofwhack

Outofwhack

Member
I did see a .5v DM measurement on the track to the cpu whilst R7704 was removed indicated an intact ESD diode and thus ok track.
Ive tried a different charger and Im getting a green light now.

So Im left wondering what else can cause bklt_pwm to remain at 0v.
 
Last edited:
You must log in or register to reply here.
Top