820-4924-A NO water damage, light on MagSafe, no fan, no booting.

MaxFix

Member
Hi,

No water damage on the board.

First value is board connected to power normally. Second value is board in SMC bypass mode:

L7130 - pulsating 12.14V-12.59V; 12.27V
L3095 - 0; 0
L7560 - pulsating 1.0V-3.0V; 3.34V
L7520 - pulsating 0.01V-0.07V; 0V
L7430 - 0V; pulsating 0.51V-0.61V
L7320 - 0V; 0V
L7310 - 0V; 0V
L7630 - 0V; 0V

please advise how to proceed.Thanks.
 

MaxFix

Member
In normal mode, 3V42 is stable? - YES
Also check SMC_RESET_L - 3.12V and 5V_S5 - pulsating 2-5V
Any pulse at ALL_SYS_PWRGD - 0V
 

MaxFix

Member
Short on all capacitors. Replaced one by one. C6422 was the bastard. Problem solved. Motherboard fixed. Extremely happy. Thanks for you help. Do you mind me asking how did you arrive to that conclusion? I understand the problem was with 5V_S5 line because the voltage was pulsating but how did you know that there was a short on those capacitors?
 
Top