iPad 4 Bluescreen WHY?

Hi,

history of the ipad:

i exchanged the digitizer about 2 months ago and everything was fine until now.

now:

the ipad shows bluescreens, reboot, again shows bluescreens etc.

it's a general problem, not just in a few apps.

Sometimes it starts and can be standby for 1 or 2 days, but also sometimes it instantly crashes when it starts.

at the beginning it just crashed if I start videoapps, i think.

then it restarted and i could do anything.

Now it crashs anytime with anything.

I updated the software- no change.

Here a video:

https://www.youtube.com/watch?v=tI6RoM-U...

What is wrong with my ipad??