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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.
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
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...
sorry for not coming back sooner but lost half my roof in storm,
your right 1V5_S3 not present tested short and it went to 0 ohms. put 0.5v through the line at 6 amps nothing gets hot?? covered it in alcohol nada? any ideas?
thank you for the replys
so green light going orange no fan spin
all power rails seem okay apart from
no all_sys_pwrgd
so from Q7950 I get
all_sys_pwrgd = 0.067V
PP1V05_SO_VMON=1.05V
PP1V5_S3RSO_VMON = 0.27V
VMON_3V3_DIV=1.067V
PP3V3_S5_VMON=3.3V
???????
Hi
i have an old mac book air giving me 3.3v on P1V5CPU_EN I can see it is created from PP3V3_S3_MEMRESET so i can see where it gets it from but i dont see how it is supposed to be reduced. could some one please help i am tired of looking at page 62 of the schematic and not...
firstly thank you both so very much for your help!
so on pin 2 of F7140 i get a diode reading of 0.14 V.
So i (with your help)have found the fault!!!!!!
when testing for a short i soldered my positive end to the fuse f7140 as this was fairly large. i must have affected the fuse because i...
So this board turned up with dead short on PPBUS_G3H turned out to be C7431 PPBUS_G3H then gave a flickering voltage from 8.5v to 4.0v but now only puts out 4v
changed U7100 have checked pins 27 and 28 get 20,2 ohms is the next move an SMC change?? or am i missing something