Fans start and stop intermitently, possible temp sensor problem?

[FanGuy213]

Hello,

So I opened up my HP Envy x360 Convert (15-eu0014nf) because I had to change the hinges. During this process, I had to disconnect the display, webcam, some signal dongles I believe and whatnot.

After putting everything back together, I noticed the fans spin up to 100% at the beginning for a few seconds during boot then they turn off.

They will keep turning on intermitently every few seconds or so.

I have done a few stress tests raising the temp of my CPU and GPU to about 100 Celcius and the fans won't come on.

During HP Fan system test, the fans work properly, so I am assuming a temperature sensor is not working properly and that's why the fans do not activate?
I do have errors though during the fan test however I can't seem to find their exact meaning.

UBX000-AQFA01-GXGH5G-J5PW03
UBX000-AQFA01-GXGH5G-J5FJ03

"The test determined there was a problem with the fan speed of the processor 1 (same for 2)  and that it might need to be changed".

What I have tried so far:
- Updated bios
- Updated Windows (W11)
- Disconnected battery, CMOS reset
- Disconnected fans one by one to see if one will work properly without the other (the one connected will do the same thing, turning on and off intermitently)

From the media you can see that:
The fans behaviour (No grinding or any type of sound at all, fans can move freely and during boot and fan test, they spin with no issues)
CPU and GPU temps get very high during the stress tests and fans do not turn on
CPU skin temperature does not go above 20 C which may be the source of the problem?

Any ideas? Have I shorted the MOBO somehow during my little hinge replacement endeavour? I'm open for suggestions. Thanks in advance

Link to video of the fans behaviour:
https://streamable.com/03zr2n

[FanGuy213]

Anyone?

[FanGuy213]

Bump

[Hawks_Eye]

Hi @FanGuy213 

Welcome to the HP Support Community! We're here to help you get back up and running.

Thanks for walking me through everything so thoroughly—it’s clear you’ve been incredibly methodical, and I’m really sorry this issue is still hanging around after all that effort. 

Let’s dig into it together and see if we can make some headway.

🔍 What the Symptoms Suggest

• The fans do spin during boot and diagnostics, so they’re mechanically functional.
• During stress tests, temps hit ~100°C, but fans stay off—this points to a sensor or control logic issue, not a fan failure.
• The CPU skin temperature staying below 20°C while internal temps soar suggests that sensor data may be misreported or misrouted.
• The error codes from the fan test indicate a problem with fan speed regulation, possibly tied to how the system interprets thermal input.

🛠️ Steps to Try Next

1. Reset EC (Embedded Controller)

This can help recalibrate fan behavior and sensor communication:

• Shut down the laptop.
• Disconnect the charger and all peripherals.
• Hold the power button for 60 seconds.
• Leave the laptop unplugged for 10–15 minutes, then reconnect and power on.

2. Check BIOS Thermal Settings

• Enter BIOS Setup (press Esc or F10 during startup).
• Look for any thermal or fan control settings—if available, enable Fan Always On.
• Save and exit.

3. Inspect Sensor Readings with HWMonitor or HWiNFO

• Use HWiNFO to check which sensors are reporting data.
• Look for anomalies—like the skin temp staying low while others spike.
• If a sensor is missing or stuck, it may be misconfigured or damaged.

4. Re-seat Fan and Sensor Connectors

Since you’ve already opened the system:

• Carefully recheck the fan connectors and any thermal sensor ribbons.
• Look for bent pins, loose connections, or signs of damage near the hinge area.

5. Try a Clean Boot

This helps rule out software interference:

• Press Windows + R, type msconfig, and hit Enter.
• Under Services, check Hide all Microsoft services, then click Disable all.
• Go to the Startup tab and disable all items.
• Restart and run a stress test again.

🧠 Could It Be a Motherboard Issue?

It’s possible—but not guaranteed. If a sensor line was damaged or shorted during the hinge repair, it could cause erratic fan behavior. However, since the fans respond in diagnostics, the control circuit still seems alive. The issue may lie in how the system interprets thermal input during normal operation.

You’ve already done a ton of the heavy lifting—let’s keep pushing and see if we can get those fans behaving properly again. 💪

If my response helped, please mark it as an Accepted Solution! ✅ It helps others and spreads support. 💙 Also, tapping "Yes" on "Was this reply helpful?" makes a big difference! Thanks! 😊

Take care, and have an amazing day!

Regards, 

Hawks_Eye

[FanGuy213]

Hello,

Frist of all, thank you for your reply. I was starting to lose hope. 

Do you know where I could find the schematics of my motherboard?

[Hawks_Eye]

@FanGuy213 

You are Welcome!

To get the motherboard details could you please share your HP unit's serial number with us via private message? 

Need help finding your product number? We've got you covered! Check out this handy guide:  

https://support.hp.com/in-en/document/ish_2039298-1862169-16 

To access your private messages, simply click the private message icon on the upper right corner of your HP Support Community profile, next to your profile name. 

We're looking forward to helping you get back up and running! 

Regards, 

Hawks_Eye

Note: Do not share any of your personal information in public, such as serial number, phone number, email ID, etc.