I have an issue with the built in sound card on the D975XBX2 motherboard that when the computer is powered up after not being on for while the sound will not work. To get the sound to work, I have to start up the computer, let it get all the way into windows (vista), shut it down completely (simply restarting does not work) and then power it back on as soon as it shuts off. I have the most up to date drivers for everything. What would cause this and more importantly; how do I fix it?
In my personal opinion the issue seems to be related to a software problem, either a driver corruption, operating system or registry issue or a required services is not being loaded.
The best option you may do to isolate such issue would be to test with a separate hard drive and perform a fresh operating system installatiion. Of course, make sure to test different speakers and headphones, and if possible test a different supported operating system, like Windows XP and disconnect any audio front panel connected to the motherboard (if any) and update the system BIOS.