The WiFi adapter is three components in one; WiFi, Bluetooth, and Miracast.
If you have a failure of one, that is usually a driver issue. If two go out at the same time, that is a hardware issue.
Get your data off of the machine and perform a RESET. Have it to perform all updates when finished before putting the data back on. On the initial act of RESET and it re-installs the operating system, when you get to the networking part of the setup and it will not connect or if it does not come up with a prompt to setup your network, then you have a serious hardware problem.
This will mean that the adapter is dead!
If this is the case, you can continue to use the tablet but will not have Bluetooth (or Miracast) by getting a USB WiFi adapter (pretty cheap). It may look a little goofy sticking out of the USB port and it will run hot but does work very well.
Just about any brand will work. That way, you would at least save the main portion of the tablet without having to buy a new one. These machines are not repairable and the WiFi adapter chip is built into the motherboard and cannot be replaced.