Melvinzill
Member
Yup. Tried two more and no change.
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A1502 2013 13? MacBook Pro Fan Spin, no chine or Display output
- Thread starter Melvinzill
- Start date
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.
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.
Post all voltages for U1950.
Do you get voltage at L1295 (pad 2)?
Do you get voltage at L1295 (pad 2)?
Melvinzill
Member
It’s 1.070V. Also now know why the jumper, pad 2 was torn off the board
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
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
If you get 3V at pin 3, is good.
Check if PLT_RESET_L comes high.
Check if PLT_RESET_L comes high.
Melvinzill
Member
Well isn’t that Pin 3?
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
So 3V3_S0 drops after 15s?
Which voltages remain present then?
Which voltages remain present then?
Melvinzill
Member
Yes. You mean Voltages on U1950?
In general, which voltages disappear from MLB?
Melvinzill
Member
What should I check? There are tons of voltages...
Usually the big coils, not too many...
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?
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?
If 3V3_S0 drops to 1.8V, you should note more incorrect voltages.
Melvinzill
Member
What should I do now?