820-00165 in S0, No PP1V05_S0 and VCORE

brunomotter

Member
Hello! This board came here with no power. It had a sticky layer of some undefined substance all over it, like a kind of oil or something. In the beginning the fan was spinning for a few seconds and then die and would do same thing if pressed power button but no fan spin/stop loop if no battery connected and just connected to power. I inspected the whole board under the microscope and could not find anything looking corroded or visually bad, so I decided to ultrasonic clean it because I thought maybe something could be stuck under PCH/CPU making the board not turn on. Now the board is stuck in S0, but no PP1V05 and obviously no VCORE. After some inspection and measurements I found that R7614 was bad, so I replaced it, but same thing. Any ideas?
 

2informaticos

Administrator
Staff member
Missing 1V05_S0 implies missing ALL_SYS_PWRGD.
Check traces, solders and components around U7600.
Post its voltages; pins 6, 12, 16, 17.
You may need to change it.

Do you get 1V2_S3 for sure?
 

brunomotter

Member
Yes, 1V2_S3 present and stable.

U7600:

Pin 6 - 1.8V
Pin 12 - 5.1V
Pin 16 - 3.3V
Pin 17 - 0V

Already replaced U7600, as it seemed a little burned but same result
 

2informaticos

Administrator
Staff member
You still have a problem at U7600 area.
Check all traces, solders and components.
U7600 receives power and enable.
 
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