Answer to "Can I upgrade from Wireless G to N?"I have changed it works OK. http://www.xlr8yourmac.com/systems/macbo... look it up
Answer to "No Sound from Mac Mini!"I had the same problem with my MAC MINI A1176 Audio Board so instead of opening the case again I have scarified 1 USB socket and inserted a USB audio divice and it works just fine. a internal can cost a 30 $ on eBAY but a USB dive can cost you 5 $.