How come my tablet won't turn on completely

Ensure your tablet is off.

Turn on the tablet, while the tablet is showing Motorola logo, press the volume down key.

Keep pressing volume down key till "Android recovery text" shows up in top left corner

Press volume up key to place tablet in Android recovery mode

While tablet is showing Android recovery screen, press and hold the power button.

While power button is pressed, press and release volume up key

You should be prompted with: wipe data/factory reset option

Using the volume down button, scroll down to “Wipe data/factory reset”

Press power to select option

Scroll down to select “Yes, delete all user data”.

Use the power button to select.

Press the Power button to reboot.

This will cause you to lose all data photos movies music apps you have on your device. It takes it back to what it was like from new. If you dont want to lose all your data you can try removing unplugging the battery for a few days so all residual power is drained from the tablet then rebooting but this will require opening the tablet. Here's a teardown guide.

Motorola Xoom Teardown

Step 7 shows battery removal . removing the battery is not necessary just disconnecting it.