Radeon hd 3450

What has the Graphics card got to do with sound? Uninstall audio drivers, restart, install latest ones. Check if the speaker is plugged in all the way.
 


Did you get a fix? The installer adds HDMI sound for the card and removes existing sound config. Go into the BIOS and if sound set to Auto, set to Enable, save & reboot. Or if already set to Enable, Disable & reboot, back to BIOS, Enable, save & reboot.

Worked for me - I'd re-installed Realtek drivers about 3 times with no luck.