Connection issues a HPM27fw and a MacBook Air (M1) 2020

[C_Mertens]

Hi,
I have a 2020 MacBook Air (M1) (macOS Sequoia 15.5), and it has been connected to my HP M27fw FHD monitor without any problems for several years. It has always been connected using a video-capable USB-C to HDMI adapter. However, this week, the monitor suddenly stopped detecting the signal. I have checked the cables and tested the monitor with a Windows laptop, and it works.
It is really frustrating that I can not use my monitor now. Do you have any idea what the problem is?

Thank you. 

[Hawks_Eye]

Hi @C_Mertens 

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

Thanks for explaining everything so clearly—it’s especially frustrating when a setup that’s worked for years suddenly stops cooperating. 

Since your HP M27fw monitor works with other devices and the issue seems isolated to your MacBook Air (M1), let’s walk through a few targeted steps to help restore the connection. 🧩🖥️

🔌 1. Power Cycle Everything

• Shut down your MacBook and unplug the monitor.
• Disconnect the USB-C to HDMI adapter.
• Wait 30 seconds, then reconnect everything and power up.

🧠 2. Try a Different Adapter or Port

• Some users have found that certain USB-C to HDMI adapters stop working after macOS updates.
• If possible, test with a different adapter—preferably one that’s DisplayLink-certified or from a known brand like Anker or Apple.

⚙️ 3. Reset Display Settings

• Go to System Settings > Displays.
• Hold Option and click Detect Displays.
• If the monitor appears, adjust resolution and refresh rate manually.

🌐 4. Disable USB Restricted Mode

macOS Ventura and later introduced a feature that can block USB-C accessories:

• Go to System Settings > Privacy & Security.
• Scroll to Security > Allow accessories to connect.
• Set it to Always.

🔄 5. Update macOS and Adapter Firmware

• Make sure your Mac is running the latest version of macOS Sequoia 15.5.
• Check the adapter manufacturer’s website for any firmware updates.

🧰 6. Try DisplayLink Manager (if using a hub)

If your adapter or dock uses DisplayLink:

• Download DisplayLink Manager from Synaptics.
• It can help restore monitor detection and manage resolution settings.

Let me know how it goes—whether the monitor lights up again or still plays hard to get. We’ll keep pushing until it’s sorted! 💪😊

If these steps do not resolve the issue, there may be a problem with the MacBook’s USB-C port itself. In this case, contacting Apple Support for further assistance would be recommended.

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