Desktop won't boot

[R_Cana]

Product: HP ENVY Desktop PC TE02-0000i (3Y3Q7AV)

Model: TE02-0003na

When plugged in the desktop power button automatically lights up without pressing it but nothing displays on the monitor. I noticed that the top fan was working just fine but the bottom one was not. Before this I kept getting the same CMOS Reset (502) error no matter how many times I let it reset. I followed the self diagnosis and repair by the HP virtual support assistant to drain the battery by holding the power button while it was unplugged but even that didn't work. I was thinking it might be a hardware error but wanted to consult with someone here to see if there was something I could do. 

[Hawks_Eye]

Hi @R_Cana 

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

Thank you for explaining the situation so clearly. It’s genuinely concerning when your desktop powers on unexpectedly, shows no display, and throws persistent CMOS Reset (502) errors. 

Let’s walk through what’s happening and how you can approach it.

 

What the CMOS Reset (502) Error Means

This error typically points to a problem with the BIOS settings or the CMOS battery. It can also be triggered by a corrupted BIOS or a failing motherboard component.

Here’s a helpful guide from HP:
HP PCs – 500, 501, or 502 error displays on a black screen
And another focused on CMOS resets:
HP PCs – Reset the CMOS

 

Steps You Can Try

1. Replace the CMOS Battery

A weak or dead CMOS battery can cause repeated reset errors.

• Power off and unplug the desktop.
• Open the case and locate the coin-cell battery (usually CR2032).
• Replace it with a new one.
• Hold the power button for 30 seconds before reconnecting power.

 

2. Reset BIOS to Default

This helps clear any corrupted settings.

• Power on and immediately press Esc repeatedly.
• Select F10 to enter BIOS Setup.
• Press F9 to load setup defaults.
• Press F10 to save and exit.

 

3. BIOS Recovery

If the system isn’t displaying anything, try this recovery method:

• Press and hold Windows + B keys.
• While holding them, press and hold the Power button for 2–3 seconds.
• Release the power button but keep holding Windows + B for 10 more seconds.
• If successful, the BIOS recovery screen should appear.

More details here:
Power ON – No-Display Issue

 

About the Bottom Fan Not Working

It’s understandable to be concerned when one fan isn’t spinning. However, many modern desktops use zero RPM fan modes, where fans only activate when temperatures rise.

• If the bottom fan only twitches or stays off during idle, it may be designed that way.
• You can test this by running a demanding task (if the system boots) and checking if the fan activates.

If the system still doesn’t boot or show display after these steps, I can help you create a USB BIOS recovery drive or guide you through checking internal connections. Just let me know what you'd prefer.

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