KG241Y Display port does not work when starts until power or DP cable is unplugged / plugged back in

Callidor

Hello. My monitor is a KG241Y S. Just yesterday I switched from an HDMI cable to a DP cable. There didn't seem to be any issues at first.

However, I've since been having a weird problem. When I power off my PC and monitor, and then turn both of them back on, the monitor will report "no signal" on the DP input mode.

The GPU's HDMI port will work fine, but none of the DP ports will. The only way I can get the monitor to recognize the input signal from the DP cable is to unplug either the power cable or the DP cable itself, specifically from the monitor-side (unplugging the DP cable from the PC and plugging it back in does not work).

Once the DP or power cable has been unplugged from the monitor and plugged back in, it will continue to work fine, until I once again shut down the PC and monitor. Shutting down just one and then turning it back on will not lead to the issue. Shutting down both, unplugging the monitor and plugging it back in before restarting both will work.

I have tested this on two completely separate PCs. My main system is running Windows 11 and and an Nvidia RTX 4060 Ti. The old PC is running Windows 10 and an an Nvidia RTX 2070. The exact same issue occurred on both systems.

This seems pretty weird. Any possibilities here other than just a defective monitor?

[Edited the thread to add model name to the title]

billsey

Check to make sure the Nvidia drivers aren't turning DP off to save power.

Callidor

https://community.acer.com/en/discussion/comment/1252880#Comment_1252880

This sounds like an intriguing possibility. I don't see any setting like this in the Nvidia control panel. Is there a specific place you can point me to?

I did a bit of googling based on your comment, and I found a lot of threads, mostly on the Nvidia forums, where people described issues similar to mine, but they always seemed to involve multiple monitor setups, whereas I'm just using a single monitor.

In the meantime, I've swapped again from DP to HDMI 2.0, which does not have this issue with this monitor, so solving it has become a little bit less urgent, but I'm still very curious.

AnhEZ28

@Callidor

Try to turn off the auto source input.

Callidor

https://community.acer.com/en/discussion/comment/1252920#Comment_1252920

Auto input is off. This problem was happening with the input set to DP.

Alexanderjulia

If your KG241Y display's DisplayPort (DP) connection fails to work upon startup and only becomes functional after unplugging and re-plugging the power or DP cable, the issue may stem from loose cable connections, power supply irregularities, or potential firmware conflicts. Begin by ensuring secure cable connections at both ends and testing the display with a different power outlet or cable. Check for firmware updates for your display and graphics card, and also test with a different DP cable. If the problem persists, consider updating graphics card drivers or consulting manufacturer support for further assistance, as the issue may involve hardware concerns that require professional diagnosis and resolution.