xoom wont turn on, frozen black screen

[yoshkapundrick]

Could you have a bad LCD with a perfectly good digitizer?

 

[spoonfork]

I had the same issue. I had to replace the USB/HDMI charge board on my Xoom2 (a known issue for these devices, where the USB socket fails). I ordered the board and it took ages to arrive. It ended up being the wrong revision. So I ordered another one and by the time I recieved it and installed, my Lipo Battery had discharged to a low 2.7V from the normal 3.7V rating (not enough to switch on the Xoom2).
I tried leaving the Motorola USB charger in for 2 days and still no go. I was able to salvage the battery by removing it and putting it on 0.1 mAh 1S charge on my programable Smart Lipo charger (which I use to charge my RC plane Lipo's). It brought the battery slowly back to 3.7 Volts after 1.5hrs of charging. I put it back in and the unit came back to life! From there, it showed up in Android as 15% charged so I plugged the Motorola USB charger in to confirm it still worked and let it do the remainder of the charge.

So my fix was,
1) Open up the unit and unscrew 4 torx bits holding the battery down.
2) Disconnect two little DC power plugs from the Mainboard.
3) Once that is done, measure with a Multimeter. Anything below 3 Volts, you will need to set your smart charger to the lowest possible mAh charge (mine was 0.1 mAh).
4) I charged it on the concrete floor of my garage and checked it often too ensure the battery had not puffed up or become hot. Be careful, as Lipo's are a fire hazzard even if you know what you are doing!
5) Once the battery reach 3.7V put the battery back in and re-assemled the unit.
6) Turn it on and finish the remainder of the charge with the Units original USB charger.

Will post again to let you know if the battery is OK or if I needed to buy another one.

Either way My Xoom2 is back up and running!