Why Doesn’t My Monitor Turn on When I Start My Computer?

In this week’s Tech 911 – a column that looks at whatever technology issues or questions you have – a Lifehacker reader is confronted with one of the most frustrating issues you can face after creating a new desktop system: something works not properly .

I’ll let Ron explain:

I recently finished building my own PC using the list of components that can be found here . I also bought this monitor for him (connected via DisplayPort cable). Everything seems to be working fine, except for one small problem: about half of the time when I turn on the power from the off state, the monitor does not display an image, and I have to turn off and try again. As far as I can tell, this is an accidental occurrence.

The mysterious case of the missing monitor

When I first read this email, I immediately thought of various troubleshooting methods that you might want to use to isolate this issue, such as narrowing down the possible answers by methodically troubleshooting.

First, chances are good that this is not a software problem. If your monitor only turns on occasionally when you start your computer, it’s too early for things like video card drivers and the like to affect your situation. This doesn’t mean you shouldn’t try to reinstall the latest Nvidia drivers , but I don’t think the problem is here, and I would put it below on my “try” list.

I think something hardware is to blame. And that doesn’t mean you have a broken monitor. In fact, I think your monitor is working fine, except for one small setting that causes some problems. I’ve used ASUS ROG Swift PG279Q as a hardware browser in the past, and I believe there is one simple setting hidden in its OSD that you can blame for your problems.

Raise your monitor settings and scroll down to System Settings. There, you want to scroll down past the “All Reset” option, which looks like it’s the last thing on the list, but it’s not. You will find a setting called “DisplayPort Deep Sleep”. Turn that off and I suspect you shouldn’t have any more problems with the monitor refusing to turn on.

If you do, you can try even more. You can disconnect the DisplayPort connection on both ends and reconnect both sides if a loose connection is to blame. You can try using a completely different DisplayPort cable. Switch to HDMI and see if you have the same problem. Switch back and make sure your monitor has selected the correct DisplayPort connection – I suspect so, but it never hurts to check.

You can try resetting your monitor using the aforementioned Reset All command. This may not solve the problem, but again, this is the idea. You can also try resetting your motherboard to factory defaults via BIOS. You can shut down your system, remove the CMOS battery , wait a few minutes, and reinsert it just in case there are any fancy settings causing these problems.

If you still have problems, you can go even further: reinstall your graphics card (take it out and plug it back in). Unplug all power cables going to your graphics card and plug them back in. Reinstall RAM. Disconnect the power cables to the motherboard (the thick 24-pin connector and the thinner 4- or 8-pin connector) and reconnect them.

I’m struggling to think of what else you can do at the moment, but it seems to me that the DisplayPort Deep Sleep setting is to blame for your problems. After all, this is a brand new computer. While faulty hardware can break at any time, I don’t think that’s the problem here. I think this annoying environment is causing you grief.


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