HP Laptop - 3.5mm Headphones & Speakers Play Simultaneously with pal1000 Realtek UAD Generic Driver

[bike3097]

• Laptop Model: HP X1G90PA
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• Audio Chip: Realtek ALC295
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• Driver Version: pal1000 Realtek UAD Generic 8912
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• Windows Version: Windows 10 iot ltsc 2021
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• Connection: 3.5mm TRS/TRRS headphone jack

Issue Description
After installing the pal1000 Realtek UAD Generic driver, inserting 3.5mm headphones does not mute the internal speakers. Both devices play audio simultaneously, and the system fails to switch the default output automatically, even with correct settings in Realtek Audio Console.

Reproduction Steps

1. Clean uninstall the original HP audio driver, reboot.
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2. Install pal1000 Realtek UAD Generic driver as admin, reboot.
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3. Play audio via internal speakers.
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4. Plug in 3.5mm headphones → both headphones and speakers play audio.

Expected Behavior

• Headphone insertion triggers automatic speaker muting.
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• System switches default audio output to headphones immediately.

Actual Behavior

• Audio plays through both headphones and speakers.
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• Default output device remains on speakers; no automatic switch.
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• Realtek Audio Console shows "Headphones plugged in" but does not apply muting.

Troubleshooting Attempted

1. Enabled "Mute rear output when front headphone plugged in" in Realtek Audio Console; disabled "Disable front panel jack detection".
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2. Set headphones as default device in Windows Sound Settings; disabled Stereo Mix.
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3. Reinstalled the driver multiple times with clean uninstalls.
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4. Verified BIOS settings: HD Audio Controller & Front Panel Audio = Enabled.
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5. Tested multiple headphones; issue persists.
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6. Confirmed no issue with HP official audio driver (speaker muting works as expected).

Additional Notes
This issue is HP-laptop-specific with the pal1000 generic UAD driver. The official HP driver handles jack detection and speaker muting correctly, indicating the generic driver lacks proper configuration for HP's customized audio hardware/firmware. No error codes in Device Manager or Event Viewer.