Hi, i am new here.
Long story short, was banging my head around A1466 820-00165-a board.
Originally came in with no backlight. Opened, of course water damage. Replaced water damaged area ( U770, R7731,R7715), started to work.
Noticed that there are some water marks around SMC, cleaned, reflowed. Also corrosion around U7100, cleaned it up, trace disappeared from c7121to C7120, ran a wire, made sure there is no short. Connected my charger from DC power supply, was taking 2,4amps, fan spins, backlight on all good, customer collected.
After week customer calls back in, saying it is not charging, i try my power supply, it is charging, try customers charger, it is not, so all blame on charger.
After a week customer comes in with new charger, still not charging, but charging fine from my DC power supply.
I tested customers charger on another a1466 and it is working fine.
So i decided to check around U7100, all voltages are present. So decided to swap U7100, and there problems begun. I replaced U7100, got 4v on PPBUS_g3h, decided that either soldering is not good or ic is faulty, so replaced one more, this time inspecting closely all pins under microscope, soldering was decent, still same 4v. replaced once more with 3rd ic, same 4v on PPBUS_g3h.
Now PPBUS_G3H is at 4V, Here are the measurements:
Green light/Orange light Present
PP3v42_g3h = 3.42V
U7100
Pin1 0v
Pin2 14v
Pin3 3.8v
Pin4 2.53v
Pin5 2.35v
Pin6 0v
Pin7 2.68v
Pin8 0.58v
Pin9 0.01v
Pin10 3.36v
Pin11 3.32v
Pin12 3.38v
Pin13 3.08v
Pin14 3.08v
Pin15 0.04v
Pin16 3.8v
Pin17 3.9v
Pin18 3.9v
Pin19 5.05v
Pin20 5.03v
Pin21 0.02v
Pin22 0v
Pin23 3.93v
Pin24 4.86v
Pin25 4.74v
Pin26 12.68v
Pin27 14.4v
Pin28 14.46v
Resistance between pins 17/18 = 3.2ohm
Resistance between pins 27/28 = 20.3ohm
All resistors around u7100 looks good and i also measured them agains schematic, they are ok.
Any help will be much appreciated. Thanks.
Long story short, was banging my head around A1466 820-00165-a board.
Originally came in with no backlight. Opened, of course water damage. Replaced water damaged area ( U770, R7731,R7715), started to work.
Noticed that there are some water marks around SMC, cleaned, reflowed. Also corrosion around U7100, cleaned it up, trace disappeared from c7121to C7120, ran a wire, made sure there is no short. Connected my charger from DC power supply, was taking 2,4amps, fan spins, backlight on all good, customer collected.
After week customer calls back in, saying it is not charging, i try my power supply, it is charging, try customers charger, it is not, so all blame on charger.
After a week customer comes in with new charger, still not charging, but charging fine from my DC power supply.
I tested customers charger on another a1466 and it is working fine.
So i decided to check around U7100, all voltages are present. So decided to swap U7100, and there problems begun. I replaced U7100, got 4v on PPBUS_g3h, decided that either soldering is not good or ic is faulty, so replaced one more, this time inspecting closely all pins under microscope, soldering was decent, still same 4v. replaced once more with 3rd ic, same 4v on PPBUS_g3h.
Now PPBUS_G3H is at 4V, Here are the measurements:
Green light/Orange light Present
PP3v42_g3h = 3.42V
U7100
Pin1 0v
Pin2 14v
Pin3 3.8v
Pin4 2.53v
Pin5 2.35v
Pin6 0v
Pin7 2.68v
Pin8 0.58v
Pin9 0.01v
Pin10 3.36v
Pin11 3.32v
Pin12 3.38v
Pin13 3.08v
Pin14 3.08v
Pin15 0.04v
Pin16 3.8v
Pin17 3.9v
Pin18 3.9v
Pin19 5.05v
Pin20 5.03v
Pin21 0.02v
Pin22 0v
Pin23 3.93v
Pin24 4.86v
Pin25 4.74v
Pin26 12.68v
Pin27 14.4v
Pin28 14.46v
Resistance between pins 17/18 = 3.2ohm
Resistance between pins 27/28 = 20.3ohm
All resistors around u7100 looks good and i also measured them agains schematic, they are ok.
Any help will be much appreciated. Thanks.
