Unlocking Droid XT912 with a Fully Broken Screen/Digitizer I am trying to pull data off a Droid Razr XT912 with a broken digitizer and screen from last summer which has been under pattern lock since then. I purchased a Micro-to-HDMI cable, which successfully displays the phone's unlock screen on my TV. I also purchased a Mini-to-USB cord so I could enter the pattern on the screen with a USB mouse. The phone, however, is not recognizing the mouse, regardless of whether it is wired or wireless.

Interestingly, plugging the Mini-to-USB into my XT907 which I got to replace the old phone makes the mouse boot right up, even though that phone has its own pattern lock. 

I'm completely lost as to why the newer model cannot recognize the device when the older one can. My only guesses are as follows:


The operating platform has been updated since last year to support the USB mouse connection. The XT907, having been in operation until April 2014, would have received the update while the XT912 was locked with no SIM since August 2013.
The phone does not support a simultaneous connection to the HDMI (via Micro) and the USB Mouse (via Mini).
The phone does not supply adequate power to the mouse. 


Any thoughts on how I might solve this riddle? If #3 is the culprit, does anyone know which adapter do I need to supply external power to a USB mouse in "on-the-go" mode? Last, is this a fool's errand and should I just ante up for a new digitizer?

Thank you in advance!
In case any one had similar problem and unable to use the mouse, I saw an article while working to find a solution for my colleague's same type of phone. It indicated that the xt912 won't provide power to the mouse so you need to connect the mouse through a powered USB hub.  You can find it on Amazon easily but make sure it is powered with a power supply. Good Luck!