DJM800 - Buttons og meters starts flashing

Hey, have anyone experienced this odd problem. 

I was dj'ing the other day and suddenly the mixer starts acting wierd og flashing.

Sound and functions on channel 1 and 4 seems normal, but cue on CH2 i flashing when im playing and channel 1 and 4.

See video for more details.

https://drive.google.com/open?id=1b3UXTlvkT9QBQTRHX0HFcSkrSNQNP-8V

https://drive.google.com/open?id=1di-awtK9IjIfAsfbd5woL4o0tE9ZXX9j

What could cause this odd problem?