[SOLVED] Displayport cable issue

Inyray

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Sep 7, 2012
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10,510
Hi everyone.
Ths is actually a longer story but im gonna try and keep it short and precise.
I have 2 monitors, Acer predator XB271HU (IPS) and Acer predator XB271HUA (TN). The IPS panel is set as my primary screen, where im using the displayport cable that was included.
For the second monitor i had to go and buy a longer displayport cable (3m)
When i boot up the pc with just the IPS monitor plugged in, everything works. But when i plug in the second monitor with the long cable i bought, the GPU doesnt wanna boot up. It just pulses in orange and i get no signal on either screens. This made me think that the problem is with the long cable, somehow interfering with the computer (weird) so i tried shutting down the computer, unplug the long cable so i just had the main monitor plugged in, and sure enough, computer boots up fine again.
Now i know that the problem appears for sure, whenever i have two displayport cables plugged in on boot. At this point i strongly suspected that either something was wrong with the displayport or something else more serious, but i decided to check if maybe it could be the cable, so i used the displayport cable that came with the second monitor (identical to the main monitor cable) plugged it in, and booted computer. It worked.
Now i can safely say that the long displayport cable i bought is causing the issue somehow.
Is the cable defect or what is going on? How can a displayport cable connected to a monitor that is not even turned on cause a computer boot failure? I thought all displayport cables were the same, or am i missing something?
 
Solution
Ah ok, the noname 3m cable should work at 1920x1080 @60Hz without problem. 2560x1440 @144Hz can work, but not always, so a different cable like Digitus 384-AK-340100-030-S should be fine too. For 4k UHD a 8K cable would be better.

In theory all DP 1.2 cables should work, but as you found out yourself, there are some differences.

Inyray

Honorable
Sep 7, 2012
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10,510
Could a faulty cable really cause the issue i had where the gpu would shut down and not deliver any signal to any monitor. Seems bizarre to me that a cable could cause that
 
if the cable is not correctly assembled, it could even damage the monitor or the whole PC. It is powered by Signal with +3.3 V
Max. voltage 16.0 V
Max. current 0.5 A
which is 8 Watt at max. and can damage components if not correctly manufactured or if it was pinched. Could result to a short in the cable.

E.g. if you cut through a USB cable, 5V and ground would be shortened most likely and the computer would shutdown immediately. If lucky, nothing would have happened to the motherboard, if not, the USB port would be fried.
 

Inyray

Honorable
Sep 7, 2012
8
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10,510


Based on what i said do you think its most likely the cable that was faulty so i need to go buy a more expensive one? Also im a bit worried about the potential damage you mentioned, both monitors and pc seems to work again so im not sure
 
If all is fine without the cable, all will work correctly, don´t worry.
Not necessarily a more expensive one but a good one. Where did you get your current one? Does it have a brand and model number?

Get a DP certified one:
https://www.displayport.org/product-category/cables-adaptors/?ps&pcat%5B0%5D=cables-connectors

Would get the Startech DISPLPORT10L or DISPL3M, depending on which is cheaper

if you wanna be sure that it will work in higher resolutions than FullHD 1080p as well, you can get a 8K certified cable:
https://www.displayport.org/product-category/cables-adaptors/?ps&pcat%5B0%5D=8k-cables&pcat%5B1%5D=cables-connectors
 

Inyray

Honorable
Sep 7, 2012
8
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10,510


It came in a plastic bag with a label that just said displayport 1.2 so i think its a cheap made in china cable xd
2560x1440 @ 144hz is the resolution and refreshrate on both monitors. Would i need a 8k cable for that?
 
Ah ok, the noname 3m cable should work at 1920x1080 @60Hz without problem. 2560x1440 @144Hz can work, but not always, so a different cable like Digitus 384-AK-340100-030-S should be fine too. For 4k UHD a 8K cable would be better.

In theory all DP 1.2 cables should work, but as you found out yourself, there are some differences.
 
Solution