C750 No Sound

[amotyka]

I recently bought a c750 on ebay from Japan. Trouble is, it doesn't have any sound and the seller is no longer registered (hmmm...)

Just wondering if there is any software fault that cause the problem or is my hardware the issue and is there any way I can check? Really annoying because it works great apart from that.

[bluedevils]

you can bypass the OS by putting it into diagnostic mode.  From there you can run sound tests.  What happens when you put it in tablet mode?  My ol' 760 does not play sound unless in tablet mode.  If so then the 750 might be broken.