A1502 fan not turning on

[myth77]

I very rarely work on macs... Received this mac, i dont know history...It seems everything is working but i have no fan spinning...I tried different fan but same thing. The problem is on FAN_RT_PWM signal... there is no voltage. On connector J6050 pin 1 and 4 voltage present, but pin 2 nothing. I checked q6060 and on r6061 the resistence seems ok. Tried nvram reset and smd reset but same thing. Also, i used the thermal camera and temperature goes to 85 C on CPU in several minutes but fan is doing nothing.
I have only two more ideas..either q5159 or something associated with cpu thermal sensor is dead or U5000 dead!?
Any other ideas?

[piernov]

Re: A1502 fan not turning on

On 820-4924 fan starts spinning only after CPU gets burning hot. If it's not throttling it's fine.

[myth77]

Re: A1502 fan not turning on

So, you are saying 85 C is not enough for apple to turn fan on? Lol

[mon2]

Re: A1502 fan not turning on

What is the voltage to ground of SMC_FAN_0_CTL ?

[myth77]

Re: A1502 fan not turning on

What is the voltage to ground of SMC_FAN_0_CTL ?

0 vol

[reformatt]

Re: A1502 fan not turning on

Just run diagnostics by pressing D during startup. Fan and tach is tested during the tests. Report back if you have an error.

Apple don't mind running the CPU's hot.