A similar issue is affecting the Surface RT tablets too
There are thousands of people waiting to buy a Surface with Windows 8 Pro, but some of those lucky enough to get their hands on one are now complaining about a couple of bugs affecting their devices.While many claim that the Surface pen stops working at random times, others report issues affecting the sound, as the tablet keeps muting itself all of a sudden.
According to a post on the Microsoft support forums, sound is unexpectedly muted on a Surface Pro while the Touch Cover is connected. Removing the keyboard basically solves the problem, while exchanging the cover with a new one doesn’t seem to make any difference.
Unsurprisingly, a similar issue affected the Surface RT tablet as well, but Microsoft is yet to release an official workaround for this.
Even though it was initially believed to be a software glitch, it appears that replacing the Touch Cover with a new one is the only choice, even though we’ve heard reports that, in some cases, the problem still persists even after getting a new cover.
“Regarding the issue of having the sound mute randomly, and in TH IT's case, unmute, please get in touch with the Surface Technical Support to exchange the Touch / Type Cover. We're still investigating the issue, however it appears that the cover may be the issue,” Steven_B, a Microsoft forum moderator and a Surface Team member, said in a blog post on the RT discussion thread.
Up until now, it looks like the Touch Cover is the only one causing the sound to get randomly muted, as all devices equipped with Type Covers are reportedly working just fine.
While this could clearly be a hardware issue affecting the covers, users are recommended to contact that local Microsoft store for more information on exchanging the faulty keyboards.