Recent content by jfursdon

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.

to be fair i did not measure these correctlyin the first place

hi so i have now got pp3v3_S5 pp3v3_sus both of these are 3.21 but still the board will not turn on

thats no to either of them PP3V3_SUS and PP3V3_SO

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

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

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

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...

just removed f7140 and get 8.56v on L7130

i got 2.2 ohms on this, is this another sensing circuit?

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