Hello,
I've got an Asus X554L series here and the sound is not working. The sound was working just the other day but it seems to work and then stop working. I completely uninstalled and reinstalled the audio driver in device manager, I ensured that the Windows audio service is running, I opened up the computer and ensured that all the cables are properly connected. I have the red X over my speakers with the message 'No audio output device is installed' in dxdiag in the sound tab, it also detects no audio devices.
When the sound was working, I could see without any problems the Realtek HD audio, but now when it is not working, there is not even a Audio device tab in the device manager anymore (and definitely no devices with a yelllow question mark either)
I have determined that the problem must be with the sound card itself and that it would need to be replaced, but I am not sure what piece to replace, and would also like to hear others opinions.
Here are the replacement parts I have been looking at on eBay, I am just not sure which one would be the defective part, but I am definitely guessing it would be (2) since that is the piece that connects directly to the motherboard, the speakrers also connect to that piece, it also connects the hard drive, and also connects to the side USB ports with the headphone jack via flex cable.
(1) http://www.ebay.ca/itm/Asus-X554L-USB-Audio-Card-Reader-IO-Board-/253021647237?hash=item3ae943f185:g:uxMAAOSwrfVZV1lh&autorefresh=true
(2) http://www.ebay.ca/itm/Asus-X554L-Board-HDD-Hard-Disk-Sata-/263065785120?hash=item3d3ff15320:g:g60AAOSwz71ZV1oF
Well, thanks for taking the time to read! I will definitely post the solution once found