The wifi antenna has two solder points. The one on the right frequently breaks loose especially if dropped. It needs soldered back on. It's seldom the antenna detaching from the board. All it takes is the antenna itself being bent a little to pop the solder joint loose. Hope this gets everyone going again.
Did you get it fixed? Could be ribbon cable, RF board or WiFi board. If holding the power button for 10 seconds to shut it down and clear the cache doesn't work it's probably a hardware issue. Have you unplugged it for 30 seconds? Also can you connect to WiFi? Update (08/07/2017): Sorry I hadn't been following this post more closely. Many times the WiFi/Bluetooth board stops working. WiFi modules are pretty cheap on Amazon and eBay. They are very easy to replace. Can't sync if the xbox can't see the controller.
I've had the same problem. In one I repaired the RF rol board was bad. Another one the customer had tried to repair and where the Wifi antenna plugged into the RF board was pulled loose. Also make sure the WiFi card and the cable connection to the Mobo are pushed in all the way. Hope you have already figured it out, please let me know if you did and what you did to repair it.
Very simple fix to the E-200. Try plugging the Drive into a Windows 8.1 PC through USB. You'll need a USB to SATA connector from an external HDD Kit available everywhere. A message will show up saying the drive has errors on it. Wait a moment then go to File Explorer. It will show up as 5 different drives. Mouse over each of the 5 partitions, right click and click repair on all 5 partitions. Windows should repair them. This has worked on all drives I have worked on with the E-200. Plug it back in to the Xbox and you're done. Hope this helps, it's worked 100% of the time for us. Kevin @ kcxboxrepair.com
Check the power ribbon. I repair these all the time and most of the time I have found bugs have been in there and left feces behind on the power ribbon which eats into the plastic. Yes bugs fecal matter does eat into the power ribbon and I have replaced or cleaned 50 or so that had this problem. I even found a spider leg shorting out one of the bare ends where it plugged into the RF board. Inspect the cable and Clean both sides well and put it back in, sometimes works. Other problems include USB, the RF board and as stated the hard drive. I have only seen one that had a blown resistor on the board out of 50 or 60 I have repaired. It's almost always something simple. Thomas; You can get the power ribbon for $4.50 on eBay, its always worth a try since it worked when you replaced the RF module it stands to reason it's something to do with the power ribbon connection. Not the power supply, not the RF since you changed it, not the common USB short, all that's left is power ribbon or MOBO (and as I said that is a o...
Open up the box and clean everything including the fans and heat-sinks; and Replace the heat-sink thermal paste. Dirt, dust and putting the Xbox in an entertainment center are almost always the reason for the red rings in the first place.