Mac won't sleep - "Idle sleep preventers: IODisplayWrangler"

Mac products
3

Hello Scania,
We request you to contact apple support, they will help you to fix this issue.
Regards,
Alok.

1
Hi,

suddenly, my MacBookPro 17", El Capitan, won't fall asleep anymore. Turns down for a few seconds perhaps, but then comes back again. 

Upon "pmset -g assertions" it says: "Idle sleep preventers: IODisplayWrangler"

I tied a couple of times resetting the SMC, as well as the NVRAM. I reinstalled the OS. I erased the disc, reinstalled the OS, reinstalled the user from backup. Nothing, always the same.

Which gives me the impression it's a hardware thing, and not a software.

Any hints? I found only a few posts on this, most of them with a solution (if at all) via the print queue - which can't be the case for me (fresh install OS X)...
2

Hello Scania,
We request you to contact apple support, they will help you to fix this issue.
Regards,
Alok.