The Lenovo Yoga 900, a sleek and stylish 2-in-1 laptop, boasts impressive specifications. However, a common complaint among users revolves around its cooling system, specifically the fan. Many report experiencing persistent fan noise, with the fan seemingly always spinning, regardless of the system load. This article delves into the reasons behind this issue, explores potential solutions, and addresses the specific concern of measuring 5V across the fan even when it's not spinning.
Understanding the Problem: A Symphony of Spins
The persistent fan activity in the Yoga 900 YSL isn't always indicative of a malfunctioning fan itself. While a faulty fan is certainly a possibility, the problem often stems from deeper software or hardware issues related to the laptop's thermal management system. Let's explore the common culprits:
* Software Issues: Incorrect BIOS settings, outdated or corrupted drivers, aggressive power profiles, and even conflicting software can lead to the fan running constantly. The laptop's operating system might misinterpret temperature readings or initiate unnecessary fan speeds, resulting in incessant spinning. This is often the easiest problem to address.
* Hardware Issues: A failing temperature sensor can provide inaccurate readings to the system, triggering the fan to run even when the system isn't overheating. Similarly, a problem with the fan's control circuitry on the motherboard could cause it to run continuously, regardless of the temperature. Dust buildup within the cooling system can also restrict airflow, causing the system to overheat and the fan to compensate by running at full speed. Finally, a faulty fan itself might be the problem, even if it receives the correct voltage.
* Aggressive Power Profiles: High-performance power profiles, often selected by default or chosen unintentionally, can instruct the system to run the fan at higher speeds even under light loads. Switching to a balanced or power-saving profile can often alleviate this.
The 5V Mystery: A Clue, Not a Conclusion
Measuring 5V across the fan terminals while it's not spinning doesn't automatically mean the fan is faulty. The 5V reading simply indicates that the power is reaching the fan. The fan's speed is controlled by a Pulse Width Modulation (PWM) signal, not just the voltage. This PWM signal, typically a varying voltage, dictates the fan's rotational speed. A constant 5V supply merely confirms power availability; it doesn't guarantee the fan's functionality or proper control. The fan might be receiving the power, but the PWM signal might be faulty or absent, preventing the fan from spinning.
Troubleshooting Steps: A Systematic Approach
Addressing the persistent fan issue requires a methodical approach. Here's a step-by-step troubleshooting guide:
1. Check for Dust Buildup: Dust accumulation is a common culprit for overheating and excessive fan noise. Carefully open the laptop (refer to Lenovo's service manual for instructions) and gently clean the fan blades and heatsink using compressed air. Avoid touching the components directly to prevent static damage.
2. Update Drivers: Ensure your laptop has the latest drivers installed, particularly for the chipset and thermal management components. Visit the Lenovo support website and download the appropriate drivers for your Yoga 900 YSL model.
current url：https://gibrtv.c171n.com/blog/fans-always-spinning-yoga-900-ysl-40032