820-00164 green light orange light no power up

jfursdon

New member
hi i have a 11" mac book air
with green light orange light no power up
board looks very clean no previouse signs of work but it may have been cleaned.

ppbus_g3h - 8.67v
pp5v_s5 - 0v

but no short to ground on pp5v_S5

following pp5v_s5 back i assume u7501 creates this

this has no 0v onvin on ppbus_s5_hs_other_isns

power supply showes 0.03 amp at 18.5v

any help would be appreciated john
 

2informaticos

Administrator
Staff member
Post some voltages for U7501; pins 23, 13, 12, 22, 29, 21, 4.
Check for any pulse (at least) at pins 12, 21, 4; if no steady voltage detected.
 

jfursdon

New member
voltages on U7501

23- 0V
13- 0V
12- 3.41V
22- 0V
29- 0.33V
21- 3.4V
4- 0V

No pulsing on 12,21,4

thank you again

john
 

jfursdon

New member
bugger
i have now embarresed myself!!!
ppbus g3ht shorted the fuse had blown and i was testing the supply side so sorry
thanks again

john f
 

JohnB8812

New member
If you have no voltage on the VIN pin of U7501 check for a short on that pin. Also inspect closely that the trace isn't broken.

PPVRTC_G3H present at 3.3 volts?
 

jfursdon

New member
okay so i sorted out short on PPBUS_G3H
it was C7582 shorted to earth
this still will not post

voltages on U7501
23- 8.59v
13- 3.43v
12- 3.41v
22- 3.29v
29- 4.98v
21- 3.4v
4- 0v

no pulsing on
12
21
4
thank you john
 

2informaticos

Administrator
Staff member
Resistance to ground at 3V_S5 coil?
U7501 is enabled, change it if no short, or low value...
 
Last edited:

2informaticos

Administrator
Staff member
Trigger SMC_ONOFF_L and check for pulse at PM_SLP_S4_L.
If not, then post PM_RSMRST_L and check if PM_PWRBTN_L drops at same time with SMC_ONOFF_L.
 

jfursdon

New member
hi so attached a small wire to R5115 to trigger SMC_ONOFF_L and nothing on PM_SLP_S4_L nothing on well 0.009v on PM_RSMRST_L and no volts on pm_pwrbtn_l so no drop.
 
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