A1502 2013 13? MacBook Pro Fan Spin, no chine or Display output

2informaticos

Administrator
Staff member
Any corrosion there?
Input voltage cannot drop so much.
Be sure the chip is correctly soldered.
You can try to force the signal, soldering 1K instead of 10K resistor.
 

Melvinzill

Member
Well the board has seen liquid damage but the are looks fine. I’ll check the chip again and if not try the 1k resistor
 

Melvinzill

Member
So with the 1k resistor it has about 3.3V on both sides of the resistor. Still doesn’t work though… No display or anything.
 

Melvinzill

Member
Also still wondering why someone who worked on the board before me ran a jumper between Pin 1 of C1297 and Pin 2 of L1295… Someone seems to have already given up on this one or it failed later
 

Melvinzill

Member
And for U1950 we get:

Pin 1 - 3.3
Pin 2 - 3.3
Pin 3 - 3.4
Pin 4 - 0 (GND)
Pin 5 - 3.4
Pin 6 - 3.4
Pin 7 - 3.4
Pin 8 - 3.4
 

Melvinzill

Member
Also super strange is the fact that pin 2 on R1950 occasionally shows 1.8V despite using the 1k resistor. If I unplug and replug power it fixes it
 

Melvinzill

Member
Also I’ve noticed pin 2 of R1950 seems to be at 3.3v for about 14s (estimate) before falling to 1.8. Same at Pin 1 so PP3V3_S0 is falling
 

Melvinzill

Member
Okay:

L7130- 12.79
L7520- 5.18
L7320- 1.71
L7310- 1.70
L7630- 1.06
L7430- 1.36
L7710- 0V
L3095- 0V

hope those help. What a frustrating board as it’s so close to working with the cpu heating up, fan spin etc…

BTW I also noticed R6131 wasn’t on the board near the SPI flash. Is that always not populated?
 
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