Dell Inpirion 3481 Fan issue

[teruger]

Hello guys

My laptop have a FAN issue, i tried with a new FAN but the issue persist.
The motherboar is LA-G714P

I measured the JFAN1 connector

pin 1: 5v
pin 2: 0v FAN1_PWM
pin 3: 3v FAN1_TACH (this pin should not be 0v if the fan is off??)
pin 4: GND

Tanks for advance!

[Diah]

which system you have?
Dell Inpirion have lack with controller.. but there are tools old from early 2003 for windows only can communicated with controller to turn it high and low depending on CPU lasting

[mon2]

Yes, it is ok to have a voltage even without a fan on the TACH pin # 3. This is due to the 10k PU on the EC side of the controller. The EC is often a 8051 style microcontroller and used for dedicated functions like keyboard scanning, fan control, etc.

[teruger]

which system you have?
Dell Inpirion have lack with controller.. but there are tools old from early 2003 for windows only can communicated with controller to turn it high and low depending on CPU lasting

I have windows 10

[teruger]

Yes, it is ok to have a voltage even without a fan on the TACH pin # 3. This is due to the 10k PU on the EC side of the controller. The EC is often a 8051 style microcontroller and used for dedicated functions like keyboard scanning, fan control, etc.

Ok, thank.
I tried for a Clean Me bios but the issue persist.
The CPU temprature in a stress test is over 70° and the cooler not turn on
I think there is a problem in the motherboard

[mon2]

How are you measuring the temp? Is it using the logic board's thermal sensor or external tools?

[mon2]

Remove all power. Meter in DIODE mode. Red meter probe to ground. Black meter probe to the point to test. Measure on pin # 2 of the fan connector. This will confirm if the GPIO pin on the EC controller is defective or not.

No power during the DIODE mode testing.

[teruger]

How are you measuring the temp? Is it using the logic board's thermal sensor or external tools?

I use a software "Hardware Monitor".
When i touch the heatsink it is very hot

[piernov]

I don't know about the fan profile on this machine, but 70°C is low for a laptop. In fact with a good stress-test it should quickly go above that. If it reaches like 95°C, throttles, but the fan never starts then that would be a problem. Maybe it is already throttling for other reasons.

[teruger]

Remove all power. Meter in DIODE mode. Red meter probe to ground. Black meter probe to the point to test. Measure on pin # 2 of the fan connector. This will confirm if the GPIO pin on the EC controller is defective or not.

No power during the DIODE mode testing.

The meter mark on

Pin 2: 815

[teruger]

I don't know about the fan profile on this machine, but 70°C is low for a laptop. In fact with a good stress-test it should quickly go above that. If it reaches like 95°C, throttles, but the fan never starts then that would be a problem. Maybe it is already throttling for other reasons.

I'll try a stress test for a long time and see what happens.