Try starting it up in "Safe Mode" and see if you can see the screen normally. If yes, while it will be limited access in that mode, you will know that the problem is software related. So then I would check the settings, and also check the tablet for bad apps, viruses, malware, etc.
If, however, it still does this in "Safe Mode", you may have to then try a "Hard Reset". Which will sadly wipe all data on the device. Should that still not resolve it, then I would try a local tech or contact the manufacturer if it is under warranty still.
To get into "Safe Mode" please do the following.
1. First turn off the tablet.
2. Next press and hold "Power" until you see the manufacturers logo on the screen, then release the power button.
3. "Quickly" press "Volume Down" and hold it for few seconds until you see the message "Safe mode: ON" or something similar.
4. If you wanted disable it, simply repeat the steps above, and you should see "Safe Mode: OFF" rather than on.