Can't go over 65hz on laptop display

[Haisuri]

Hi,

I was testing overclocking the displays of laptops, both 60hz, a while ago and on one laptop with an Intel UHD 620, I reached up to 78hz. While on the other laptop with a Nvidia GTX 960M and Intel HD 530 only got up to 65hz and then showed a black screen on 66hz and anything higher.

Laptop 1: Dell Vostro 3490, Intel UHD 620
Laptop 2: Dell XPS 15 9550, GTX 960M, Intel HD 530

The resolution for the laptop 1 was 1366x768 while on laptop 2 it was 1080p.

I tried testing lower resolutions on laptop 2 such as 800x600 on 66hz but it would still be a black screen. Laptop 2's display was named SHP1453 on CRU. 66hz on 1080p is 163MHZ.

Is it there any fix to go higher? Or am I just locked to 65hz by hardware or drivers?

I appreciate any help you may offer, thanks!

[ToastyX]

Black screen is a hardware limitation. Lower resolutions won't help because laptop screens usually don't have scalers.

[Haisuri]

Alright, thanks for the reply.