There is nothing wrong with the tablet as there have been no reports regarding this WiFi issue. Indeed, the tablet needs to be in the close proximity of a WiFi signal broadcaster (usually a router). Most likely this is the reason you can't see any wireless networks. On the other hand, please use the built-in settings of your tablet and perform a factory reset using Settings > Privacy > Factory data reset. If it is a software related problem it will be fixed by resetting the tablet to factory defaults. Please notice that all applications and data installed on the internal storage device will be deleted after this process.