Webcam's Built-in Mic Won't Work

Windows 7 Ultimate
Microsoft LifeCam HD-5001

Microphone doesn't work at all. Depending on the installation, Device Manager says either that there are no drivers installed, or that I already have the latest driver.

Have tried firmware update, the USELESS Windows 7 Troubleshooter, and reinstalling drivers. Still no audio, and sometimes no video, saying "There is No Camera Connected to this Computer"

Had the exact same problem with Logitech C600. Any ideas?

It is a builtin device on ASUS VK248H 24" LCD display.
It has been working flawlessly since Nov. 2014 when it was purchased to connect via DVI cable to
a MSI mobo with AMD A4-3400 APU with 8GB
OS: Win7 Home Premium SP1

Skype v7.10.85.101 was the latest upgrade and it seems to coincide with the timing of this mishap. Is it a coincidence or may be correlated? :-(

It is noted that this thread seems to be dead, but the only one accurately described as my problem. All others seem to be webcam itself malfunction physical or driver issues, but a partial like mine.
Am I the only one got bit with this bug? :-o