The chromo noria is stuck on the andorid logo

Factory reset maybe the best choice if you cannot open the machine.

Step 1. Turn the tablet off by using power off option if the tablet turns on or Pressing and holding down the Vol. UP key and the Power Button until the screen goes black.

Step 2. Press and hold both volume buttons, while holding Vol. UP & Vol. DOWN you will press and hold the power button for exactly 1 second (count on your head or say it out loud -Mississippi one-) and release the power button BUT KEEP HOLDING THE VOLUME KEYS DOWN.

Step 3. You will hold down the Volume keys until you see the screen turn on and the logo show up. (WHEN YOU SEE YOUR TABLET LOGO INMEDIATELY RELEASE THE VOLUME BUTTONS)