GSYNC display makes asus mobo give 77 error after standby

[kefjeuh93]

Short story:

when i put my pc into sleep mode and come back out of it with my GSYNC display hooked up to it,
my pc crashed and doens't want to boot anymore. It's stuck on error code 77 unless I unplug my gsync display.
I can plug it in later and then it works again.

So what is going wrong then?
Is the screen causing my system to crash ?
I have a XL2420G from BENQ
Gsync is working fine.


OLD story, When I thought it was my ram:

Spoiler

So what happens is the following:

1. PC goes into standy because of me or automatically
2. PC comes out of standby by me pressing mouse or keyboard
3. fans start spinning
4. Screens stay black
5. Asus maximus ranger gives error code 77. (cmos reset didn't help, replacing memory after this step gives me 76)
6. I disable the psu
7. make sure the power is out of the system by trying to start it
(If i don't let the power out of the system. It stays on error 77 every boot)
8. Turn psu back on
9. Turn PC on
10. And then it says overclocking failed (probably the XMP i think)
11. I go into bios. Leave the settings as they were (xmp profile 1)
12. Save and exit.
13. PC boots normal again

So i did not do any additional overclocking on the cpu.
Stock clock is 4ghz and turbo is 4.4ghz.
Memory runs fine on 1600mhz and timings are 9-9-9-24

What's in the pc:
cpu: i7-4970k
ram: 16gb corsair vengance 1600mhz 9-9-9-24 XMP (memtest gave no issues)
gpu: Gtx 980
mobo: Asus maximus ranger
psu: Corsair Rm750
ssd and hdd

 

[kefjeuh93]

Wow, apparently it was the display port cable that was faulty.
It displayed my image fine and G-sync was also working fine, so I didn't think it would have been the cable causing the issue.

So i used another one and now its working fine.