If the following doesn't work, you have a serious hardware issue that will probably require replacement by Motorola: (I know you already did a reset, but try the first method....you are stock, right?)
Remove and remount the battery and power up
If the phone still does not boot up to the MOTOBLUR screen, then perform the following Factory Reset instructions:
- Power off the phone, press and hold the Volume down button and Power button simultaneously while powering up the unit.
- Screen will come up with "Fastboot" at the top of the screen, press Volume down key to cycle through choices until you get "Android Recovery", then press Volume up key to boot in this mode
- Wait for the "triangle ! / Android" screen then go on to step 4
- Press both Volume up and Volume down key simultaneously. A Recovery Menu will come up
- Tap on Volume down key until "wipe data/factory reset" is highlighted, and tap Power button. Another Confirmation screen will come. Tap on Volume down key until coming to Yes and tap Power button
- After userdata is cleared, the "reboot system now" option will be highlighted by Default. Tap Power button
- Phone will reboot to initial setup MOTOBLUR screen.
To Perform a Factory Data Reset through settings menu:
- From the Home screen, press Menu
- Touch Settings
- Touch Privacy
- Touch Factory data reset (Read notes for other options)
- Touch Reset Phone
- Touch Erase Everything
Note: Contact your service provider if you need to reset/clear phone remotely.