A1466 (820-00165) green/orange light, but no fan.

[highvoltage]

Hi there,

I have an A1466 that suddenly went out.

Magsafe turns green, then orange, but MB has no fanspin.

An inspection under the microscope showed no corrosion, but the board was very dusty.

I am using a cut off original Magsafe cable connected to my DC power supply.

I am a noob in MacBook repair, but I have experience in repairing iPhones and reading schematics.

What I have tried so far:

I went through this diagram: https://logi.wiki/index.php?title=File:G3_-_S3_Ivy_Bridge_-_Broadwell.drawio.png

All seems to be right, until here.



Many thanks in advance,
Dom

 

[2informaticos]

First of all, welcome to the forum!

PM_SLP_S3_L cycling, or just pulsing 1-2 times when connect charger?
The S0 voltages controlled by it, should also pulse; check that.

Check if board stays on in SMC bypass.

 

[highvoltage]

I have checked PM_SLP_S3_L now. It's cycling every 4.2 second up to 3.44 volt.

SMC bypass seems not to be working.
I've tried to shorten SMC_ONOFF_L to GND while plugging charger in and hold it for about 5 - 10 seconds. no fanspin.

 

[2informaticos]

Check for pulse at all big coils.
Also check output rails from pages 57/58.
ALL_SYS_PWRGD pulsing too?

 

[highvoltage]

Check for pulse at all big coils.
L2920 pulsing
L7750 pulsing
L7310 pulsing
L7320 pulsing
L7630 pulsing
L7430 pulsing
L7560 not pulsing
L7520 pulsing
L7130 not pulsing
L3095 not pulsing
L7701 not pulsing


Also check output rails from pages 57/58.
PP1V8_S3 at R7829 is pulsing
PP1V05_SUS at C7841 seems to be stable
PP1V5_S0 at R8155 is pulsing
PP3V3_SUS at R8020 stable
PP1V5_S0SW_AUDIO_HDA at R8041 is pulsing
PP3V3_S4 at R8000 is pulsing
PP3V3_S0SW_SSD_FET_R at U8070 is pulsing
PP1V05_S0SW_PCH_HSIO at U8005 is pulsing
PP3V3_S3 at R8011 is pulsing
PP3V3_S0_FET_R at U8030 is pulsing
PP3V3_S4SW_SNS at R8050 is pulsing
PP5V_S0 at R8081 is pulsing
PP1V05_S0SW_PCH_HSIO at Q8060 is pulsing
PP1V05_S0 at Q8060 is pulsing


ALL_SYS_PWRGD pulsing too?
yes

 

[2informaticos]

Check for pulse at pins 7 & 3 of U1950.
PLT_RESET_L pulsing too?

 

[highvoltage]

yes, pins 7 & 3 of U1950 and PLT_RESET_L are pulsing

 

[2informaticos]

Check all SPI Bus Termination resistors and theyr traces.
Clean J6100 too.

 

[highvoltage]

R6110 --> 15 Ohm
R6111 --> 15 Ohm
R6112 --> 15 Ohm
R6113 --> 15 Ohm
R6114 --> 24.9 Ohm
R6115 --> 15 Ohm
R6116 --> 15 Ohm
R6117 --> 15 Ohm
R6118 --> 15 Ohm
R6119 --> 15 Ohm
R6120 --> 43 Ohm
R6121 --> 43 Ohm
R6122 --> 43 Ohm
R6123 --> 24.9 Ohm
R6125 --> 43 Ohm
R6126 --> 43 Ohm
R6127 --> 43 Ohm
R6128 --> 24.9 Ohm
R6130 --> 43 Ohm
R6131 --> 43 Ohm
R6132 --> 43 Ohm
R6133 --> 43 Ohm

all resistors seem to be fine.

J6100 was very clean, nothing to do there.

But I have found something that looks like corrosion on U6101.
I have removed it with isopropyl alcohol. Still no fanspin.

 

[2informaticos]

Add leaded solder on U6101 pads and traces.
Be sure to get good contacts.
Change the chip if needed...

 

[highvoltage]

One pad was ripped of: SPIROM_USE_MLB. I have to recreate it.

And my fault: I have lost U6101 and I can't find it...

U6101 is called 74LVC1G99. It seems to be a 3-state gate in SOT833 package.

I have ordered them now. Keep you updated...

 

[highvoltage]

Hi again,

changed U6101 now. But still same issue.

 

[2informaticos]

Be sure to have good solders and traces there.
Check continuity between pin 5 of U6101 and R1632.
Touch the pins directly when measure; not the pads from board.

 

[highvoltage]

Checked continuity. Seems to be good. But I will give up this device, it's too time consuming.