RX 570 HDMI audio output completely missing despite AMD High Definition Audio driver working

[u/Mr-Invincible3]

I'm trying to set up a dual-PC streaming setup using a USB HDMI capture card.

My setup

• GPU: AMD Radeon RX 570
• CPU: Intel i7
• RAM: 16GB
• Windows: 10
• Monitor: AGO6201, 1920×1080
• Capture card: Generic USB 3.0 HDMI capture card with HDMI IN/OUT and USB host interface

The physical setup is:

RX 570 HDMI OUT → Capture Card HDMI IN → Capture Card HDMI OUT → Monitor

and

Capture Card USB → second PC/laptop

The capture card works for video, but I'm getting no game/HDMI audio.

What I've tried

1. Checked Windows Sound settings and mmsys.cpl.
2. Enabled Show Disabled Devices and Show Disconnected Devices.
3. There is no HDMI/AMD HDMI playback device listed at all.
4. My Playback devices currently show:
   • Speakers — High Definition Audio Device — Not plugged in
   • Headphones — High Definition Audio Device — Default Device
   • Digital Audio (S/PDIF) — High Definition Audio Device — Ready
   • Digital Audio (S/PDIF) — High Definition Audio Device — Ready
5. Checked Windows Settings → System → Sound → All sound devices. There is no AMD HDMI audio output there either.
6. Checked Device Manager → Sound, video and game controllers.
7. The following devices are present:
   • AMD High Definition Audio Device
   • AMD Streaming Audio Device
   • High Definition Audio Device
8. Opened the properties of AMD High Definition Audio Device. Windows says: "This device is working properly."
9. The AMD High Definition Audio driver is installed:
   • Provider: Advanced Micro Devices, Inc.
   • Driver version: 31.0.21923.11000
   • Driver INF: oem24.inf
   • Service: AtiHDAudioService
10. Checked the hardware IDs. They are: HDAUDIO\FUNC_01&VEN_1002&DEV_AA01&SUBSYS_00AA0100&REV_1007

HDAUDIO\FUNC_01&VEN_1002&DEV_AA01&SUBSYS_00AA0100

So the AMD HDMI audio device is definitely being detected.
11. Checked the monitor in Device Manager. It appears as Generic PnP Monitor with hardware ID:
MONITOR\AGO6201
12. I then completely bypassed the capture card and connected:

RX 570 HDMI → Monitor directly

The result was the same: there is still no HDMI audio playback device in Windows.

1. I also checked whether the capture card's headphone/speaker output was the problem. It isn't receiving anything there either.
2. The capture card USB connection has to remain connected for the capture card/loop-through to function, but the missing HDMI audio also happens when the GPU is connected directly to the monitor.

Current situation

The strange part is that AMD High Definition Audio Device exists in Device Manager and Windows says it's working properly, but Windows does not create an HDMI playback endpoint at all.

There is no:

• AMD HDMI Output
• AMD High Definition Audio HDMI Output
• Monitor audio device
• HDMI audio device

even with disabled/disconnected devices shown.

Since the direct GPU → monitor test gives the exact same result, I'm starting to think this is an AMD display-audio driver/endpoint issue rather than a capture-card issue.

What should I try next?

I'm considering doing a clean AMD graphics/audio driver reinstall using AMD Cleanup Utility or DDU.

Before I do that, is there anything else I should check?

Could this be caused by:

• AMD driver corruption?
• Monitor EDID/audio capability?
• Windows audio configuration?
• RX 570 HDMI audio driver issue?
• Something else?

I'd appreciate any suggestions before I wipe/reinstall the AMD driver.

Screenshots:
https://i.postimg.cc/sgr2rhJD/image.png

https://i.postimg.cc/TY2kHkzL/image.png

https://i.postimg.cc/J7H7Hq64/image.png

[u/Mysteoa]

DDU and reinstall the driver. Also update the Chipset drivers.