I have a Polaroid 7'' Dual Core PMID702DC tablet with Android 4.1.1 Jelly Bean and I can't turn on Wi-Fi! When I turn it on, I got to Settings > Wi-Fi and it says that it's on but the button is gray and on the right it says 'Turning on Wi-Fi' but it doesn't turn on and a few minutes later it goes back to Off! I've whacked it on the back a few times and it doesn't turn on! What do I do???
Are you currently on a Jelly Bean ROM? I am using the Team Baked Jelly Bean ROM which is an AOKP based ROM. It seems really great so far and I would recommend giving it a try. You can get it through the Goo Manager app.
As we’ve seen over the last few days, folks are hard at work creating Jelly Bean ROMs for a variety of devices. Up to this point, work seems to be limited to smartphones or Nexus tablets. That appears to have changed with some work done by user randomblame over at XDA. He has succeeded in creating an SDK port of Jelly Bean for an Acer Iconia A500.