Massive delay with one of my 2000's lately, middle screen stuttering rather than smooth rotation.

Have had my 2000's around 3-4 years now and haven't experienced any issues like this. I tried updating to the latest firmware hoping that would solve the issue, which didn't seem to solve anything. Had to unplug from the wall after update as the whole deck just froze when rebooting.

They are still useable, and this only seems to happen intermittently. I use USB sticks with Rekordbox and have recently starting added a symbol (  ·  ) to tag certain tracks was wondering if this would affect the performance (will remove them and try again tomorrow) 

Here's a video to show the problem at its worst https://vid.me/uDZn