Help Asus X421EAYB Rev 2.0 PROCHOT# pulled to 0volts

[Carlos Simbaña]

Hello, I need help with this laptop, which powers on and shows video, but it’s extremely slow and the fan spins at maximum speed from the very first second.
When measuring PROCHOT#, it reads 0 volts, which limits the processor speed. I’ve been checking the charging circuit and everything seems to be fine. Additionally, I’ve already reprogrammed the main BIOS and the EC BIOS. If someone could give me a hand with whether I should replace the EC, or which signal I should measure to determine the fault, I would really appreciate it. Regards.

[mon2]

Which charger ic is onboard?

Be sure to use the official OEM power rated adapter.

Review each sensor that is most likely smbus (scl/sda) interfaced. If a sensor is missing, CPU speed will be throttled.

[Carlos Simbaña]

Which charger ic is onboard?

Be sure to use the official OEM power rated adapter.

Review each sensor that is most likely smbus (scl/sda) interfaced. If a sensor is missing, CPU speed will be throttled.

The charger IC is a BQ24780S

[mon2]

Remove all power. Meter in resistance mode. Measure the resistance between the srn and the srp pins.

What is the full path resistance?

[Carlos Simbaña]

The resistance between SRN and SRP is 20 ohms.
The impedance of SRN and SRP is around 1.6 megaohms

[mon2]

Path resistance matches the TI datasheet / reference design.

What is the voltage on ILIM pin?