ASUS Zenbook 15 OLED AMD Ryzen 9 7940HS USB-C Display Not Working Fix Windows 11

The USB-C port on your ASUS Zenbook 15 OLED AMD Ryzen 9 7940HS does not output video to an external monitor – the connected monitor shows no signal when using a USB-C to HDMI or USB-C to DisplayPort adapter, or a USB-C dock monitor output does not work. AMD USB4 driver updates and correct adapter selection restore USB-C display output on the Zenbook 15 OLED AMD.

This guide covers AMD USB4 driver updates, DisplayPort alt mode configuration, and adapter requirements for the ASUS Zenbook 15 OLED AMD Ryzen 9 7940HS in Windows 11.

“Zenbook 15 OLED AMD USB-C to monitor showed nothing. My old USB-C adapter only charged, no video. Bought USB-C to DisplayPort 1.4 adapter rated for video. After AMD USB4 driver update, monitor appeared immediately.” – Sharifah, content strategist from Damansara

Why USB-C Display Does Not Work on Zenbook 15 OLED AMD

The ASUS Zenbook 15 OLED AMD Ryzen 9 7940HS USB-C port uses AMD USB4 for display output via DisplayPort alt mode. DisplayPort alt mode requires two driver components working together: the AMD USB4 controller driver (manages USB4 protocol and alt mode negotiation) and the AMD Radeon display driver (manages the display signal generation). Without the AMD USB4 driver, the USB-C port only provides USB power delivery and USB data – the DisplayPort alt mode negotiation that tells the adapter to switch to video output mode does not occur, resulting in no display signal regardless of the adapter type connected.

• AMD USB4 controller driver missing – DisplayPort alt mode negotiation not occurring
• USB-C adapter does not support DisplayPort alt mode – only charges, no video capability
• AMD Radeon driver outdated – display output not initialized for USB4 alt mode path
• Monitor not detected after alt mode activation – requires Windows Display Settings Detect

Fix 1 – Update AMD USB4 and Radeon Drivers

Go to asus.com/support and search for Zenbook 15 OLED model number. Download and install AMD USB4 Controller driver and AMD Radeon Graphics driver for Windows 11. Install both and restart. After restart, connect the USB-C adapter to the Zenbook 15 OLED AMD USB-C port, then connect the monitor cable to the adapter. Right-click desktop – Display settings – Detect. The external monitor should appear as a second display within 10-15 seconds of adapter connection once the AMD USB4 driver completes the DisplayPort alt mode negotiation handshake with the adapter.

Fix 2 – Verify Adapter Supports DisplayPort Alt Mode

Confirm the USB-C adapter or cable explicitly states DisplayPort alt mode support, video output, or DP alt mode on the product packaging or specifications. A USB-C to HDMI or USB-C to DisplayPort adapter that only supports USB charging (common with generic or low-cost adapters) does not carry video signals regardless of the Zenbook 15 OLED AMD USB4 driver state. Purchase an adapter specifically labeled for video output such as ANKER USB-C to HDMI 4K, Belkin USB-C to DisplayPort 1.4, or a USB4 certified hub with display output. These adapters actively negotiate DisplayPort alt mode with the USB4 host port.

Test USB-C Port Display with Direct Connection

If available, test with a USB-C to USB-C cable directly from the Zenbook 15 OLED AMD USB-C port to a monitor that has a USB-C input supporting DisplayPort (many recent monitors have this). A direct USB-C cable connection eliminates the adapter as a variable and confirms the Zenbook 15 OLED AMD USB4 port DisplayPort alt mode is functioning. If the direct USB-C connection works but an adapter does not, the adapter is incompatible. If neither works, the AMD USB4 or Radeon driver needs attention before any adapter will provide display output.

Fix 3 – Update ASUS Zenbook 15 OLED BIOS

Download and install BIOS update for the Zenbook 15 OLED AMD from asus.com/support. Updated BIOS includes AMD AGESA firmware improvements that affect USB4 port initialization and DisplayPort alt mode capability advertisement. Some Zenbook 15 OLED AMD BIOS versions had USB4 alt mode negotiation timing issues that prevented DisplayPort alt mode from activating within the standard adapter detection window – updated BIOS extends this negotiation window and ensures USB4 DisplayPort alt mode negotiation completes successfully with a wider range of USB-C display adapters and hubs.

Fix 4 – Configure Display in AMD Radeon Software

Open AMD Radeon Software (right-click desktop – AMD Radeon Software). Go to Display tab. After connecting the USB-C monitor adapter, the external display should appear in AMD Radeon Software Display settings. If it shows as detected but disabled, click Enable. AMD Radeon Software sometimes shows the USB-C connected display before Windows Display Settings recognizes it, allowing activation directly in the AMD interface. Set the resolution to the monitor’s native resolution and the refresh rate to its maximum supported value through AMD Radeon Software for the Zenbook 15 OLED AMD USB4 display output.

Frequently Asked Questions

Why is USB-C display not working on ASUS Zenbook 15 OLED AMD Ryzen 9 7940HS?

AMD USB4 controller driver missing – DisplayPort alt mode negotiation not occurring. Update AMD USB4 and Radeon driver from ASUS Support. Verify adapter supports DisplayPort alt mode video output.

How do I connect external monitor via USB-C to ASUS Zenbook 15 OLED?

AMD USB4 + Radeon driver update from ASUS Support. Use adapter explicitly rated for video output (DisplayPort alt mode). Display Settings – Detect after connecting.

Does ASUS Zenbook 15 OLED AMD Ryzen 9 7940HS have Thunderbolt 4?

USB4 Gen 2 (40Gbps), not Thunderbolt 4. Supports DisplayPort alt mode and USB docks. No Thunderbolt 4 PCIe eGPU tunneling.

What USB-C adapters work with ASUS Zenbook 15 OLED AMD?

USB-C to DisplayPort 1.4 or USB-C to HDMI 2.0 adapters with explicit DisplayPort alt mode video support. USB4 certified hubs. Passive USB-C to VGA adapters do not work.

Conclusion

ASUS Zenbook 15 OLED AMD Ryzen 9 7940HS USB-C display not working in Windows 11 is resolved by updating both AMD USB4 controller driver and AMD Radeon driver from ASUS Support for correct DisplayPort alt mode negotiation. Adapters must explicitly support DisplayPort alt mode video output – charging-only USB-C adapters do not carry display signals regardless of driver state. ASUS BIOS update improves USB4 alt mode negotiation timing for compatibility with a wider range of adapters. AMD Radeon Software Display tab provides alternative display activation when Windows Display Settings fails to auto-detect the USB-C connected monitor.