Macbook Air A1466 820-00165 green light no fan spin

[kingskie]

Hi All,

I got macbook air 820-00165 with green light but no fan spin.
Measurements:

PPBUS_G3H = 8.14V
PP3V3_S5 = 0V
PP5V_S5 = 0V
SMC_WAKE_L = 3.12V
SMC_ONOFF_L = 3.4V
SMC_RESET_L = 3.38V

should i change the U7501 first?

[mon2]

Re: Macbook Air A1466 820-00165 green light no fan spin

No, measure the voltage to ground of:

SMBUS_SMC_5_G3_SCL
SMBUS_SMC_5_G3_SDA

Post the measurements.

[kingskie]

Re: Macbook Air A1466 820-00165 green light no fan spin

no, measure the voltage to ground of:

smbus_smc_5_g3_scl
smbus_smc_5_g3_sda

post the measurements.

smbus_smc_5_g3_scl = 0.492
smbus_smc_5_g3_sda = 0.491

[mon2]

Re: Macbook Air A1466 820-00165 green light no fan spin

I think you are in DIODE mode?

Meter in DC volts (10 volts or higher).

Red meter probe to point to test.
Black meter probe to ground (shield is ok).

Post each voltage measurement.

[kingskie]

Re: Macbook Air A1466 820-00165 green light no fan spin

I think you are in DIODE mode?

Meter in DC volts (10 volts or higher).

Red meter probe to point to test.
Black meter probe to ground (shield is ok).

Post each voltage measurement.

sorry @mon2 it is 3.4V for both

[mon2]

Re: Macbook Air A1466 820-00165 green light no fan spin

Voltage is correct and confirms the required pull-up resistors are present.

The SMC has to communicate with the ISL chip to boost the ppbus_g3h voltage. Your voltage is lower so this event did not take place. Communication is over these SMBUS lines.

Remove all power. Meter in resistance mode.

Place one probe on a point closest to the ISL chip to measure the smbus_smc_5_g3_scl line. Other meter probe to a point closest to the SMC chip, same line to test. Sometimes, with liquid damage / corrosion, the trace is broken for these interface lines. So you can see the 3v4 but the smc is unable to communicate with the ppbus_g3h ISL chip. Confirm that the traces are not broken with a resistance check. If your meter beeps a tone in diode mode, you can use it for the same purpose.

[kingskie]

Re: Macbook Air A1466 820-00165 green light no fan spin

Voltage is correct and confirms the required pull-up resistors are present.

The SMC has to communicate with the ISL chip to boost the ppbus_g3h voltage. Your voltage is lower so this event did not take place. Communication is over these SMBUS lines.

Remove all power. Meter in resistance mode.

Place one probe on a point closest to the ISL chip to measure the smbus_smc_5_g3_scl line. Other meter probe to a point closest to the SMC chip, same line to test. Sometimes, with liquid damage / corrosion, the trace is broken for these interface lines. So you can see the 3v4 but the smc is unable to communicate with the ppbus_g3h ISL chip. Confirm that the traces are not broken with a resistance check. If your meter beeps a tone in diode mode, you can use it for the same purpose.

i measure both path and all beeps. should i change the ISL chip?
the SMC_BC_ACOK is 3.38V. normally should be 3.42V right?

N.B
there is no sign of liquid damage or corrosion

[kingskie]

Re: Macbook Air A1466 820-00165 green light no fan spin

anyone can help?

[reformatt]

Re: Macbook Air A1466 820-00165 green light no fan spin

If PPBUS_G3H is 8.1V, then your ISL is working fine. It should be 8.6V (with no battery attached) when the SMC is properly running. So 8.1V means your issue is the SMC.

Check J6100 first for corrosion/crap or any bug shit that is bridging pins. If ok, then check around U5110 (provides SMC_RESET_L and PP3V3_S5_AVREF_SMC), presence of the latter at L5001. Check C5002 for presence of PP3V42_G3H, C5010 for PP1V2_S5_SMC_VDDC. These are the basic areas to check before anything else.

[reformatt]

Re: Macbook Air A1466 820-00165 green light no fan spin

Well thinking about it, PPBUS_G3H should be 8.3V without the SMC. So just double check that (make sure battery is not connected).

[astrotek]

Re: Macbook Air A1466 820-00165 green light no fan spin

Hi All,

I got macbook air 820-00165 with green light but no fan spin.
Measurements:

PPBUS_G3H = 8.14V
PP3V3_S5 = 0V
PP5V_S5 = 0V
SMC_WAKE_L = 3.12V
SMC_ONOFF_L = 3.4V
SMC_RESET_L = 3.38V

should i change the U7501 first?

Thats probably a SMC IC ISSUE = PPBUS_G3H it should be 8.6V