New 27" IPS LG Monitor

[Wesley57]

Just bought a new 27" Monitor for our P71126s Wow, what a difference!
Recommendations on a HDMI Card to enable sound capability for monitor via HDMI

[Echo_Lake]

@Wesley57

Thank you for posting on HP Support Community.

Don't worry as I'll be glad to help, I have a few troubleshooting steps we could try to fix the issue:  

Windows Update and HP Support Assistant will install all the latest drivers available for your computer

To check for updates now, select the Start button, and then go to Settings  > Update & security  > Windows Update, and select Check for updates.

Install updates from HP Support Assistant: Go to Download HP Support Assistant to install the tool.

1. To open HP Support Assistant, double-click the HP Support Assistant icon .
2. Click My devices in the top menu, and then click Updates in My PC
3. Click Check for updates and messages to scan for new updates.
4. Review the list of updates. Updates with a yellow information icon are recommended. Updates with a blue information icon are optional.
5. Click the update name for a description, version number, and file size.
6. Select the box next to any updates you want to install, and then click Download and install.

BIOS Update: Follow steps from the link: https://support.hp.com/in-en/document/c00007682

Hope this helps! Keep me posted for further assistance.
Please click “Accept as Solution” if you feel my post solved your issue, it will help others find the solution.

[Huffer]

HDMI is going to be provided by a video card. Any fairly recent PCIe video card will have an HDMI port and if you attach the monitor to that, you will get both video and sound output out of it. 

https://support.hp.com/us-en/document/c03042936

Even something cheap like this:

https://www.amazon.com/ZOTAC-GeForce-Profile-Graphic-ZT-71304-20L/dp/B01E9Z2D60/ref=sr_1_3?dchild=1&...

Post back with any more questions and please accept as solution if this is the info you needed.