random black screen on DK2 display

Hello everyone, I have some issues with an Oculus DK2 that was bought around 2016. We use it in our lab, but not to play games, we prepare some scenes with unity and then we wear the headset to just stay immersed there for some fixed amount of time.

Every now and then the display in the headset turns black, even if the leds on the headset are still on and we can still see the image on the pc screen moving according to the movements of the head. When the headset display turns black, the led of the tracking camera turns off for a second and then turns on again, the image on the computer screen has a lag but then starts moving normally again, following the movements of the person, however the person wearing the headset sees black for the entire time.

We are using the same notebook with an HTC vive headset and everything runs smoothly.

the specs are the following, the pc is vr ready:

cpu: i7 8750H

gpu: 1060 6 gb

ram: 16 gb

graphic card driver: 419.35

Unity version used: 5.2.2

Oculus runtime: 0.8

Do you have any idea on how to fix this? thanks a lot