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Why Won't My Monitor Turn On When I Start My PC?


In this week’s edition of Tech 911—the column that addresses any and all technological troubles or questions you have—a Lifehacker reader is dealing with one of the more annoying problems you can face after building your brand-new desktop system: something not working right.

I’ll let Ron explain:

I recently finished building my own PC using the component list found

here

. I also bought

this monitor

for it (connected via DisplayPort cable). Things seem to be working just fine except for one small problem: about half the time when I power up from a shut down state the monitor gives

no display and I have to shut down and try again. It appears to be a random manifestation,

as far as I can tell.

The mysterious case of the missing monitor

When I first read this email, my mind immediately jumped to all the different troubleshooting techniques you might want to use to isolate this problem—as in, to narrow down to the potential answer by methodically eliminating causes.

First, odds are good this isn’t a software issue. If your monitor is only occasionally turning on when you start your computer, that’s far too early in the process for things like graphics card drivers and what-have-you to be affecting your situation. That’s not to say you shouldn’t try reinstalling the latest Nvidia drivers, but I don’t think that’s the issue here, and I’d put that option lower on my “to try” list.

I think something hardware-related is to blame, here. And that’s not to say you have a broken monitor. In fact, I think your monitor is working fine, minus one little setting that’s triggering some issues. I’ve used the ASUS ROG Swift PG279Q before in my past life as a hardware reviewer, and I believe there’s one, simple setting buried in its on-screen display that you can blame for your problems.

Pull up the monitor’s settings and scroll down to “System Setup.” In there, you’ll want to scroll down past the “All Reset” option, which looks like it’s the last thing on the list, but isn’t. You’ll find an setting called “DisplayPort Deep Sleep.” Turn that off, and I suspect you won’t have any more issues with your monitor refusing to power on.

If you do, there are even more things you can try. You could unplug the DisplayPort connection on both ends and plug both sides back in again, in case a loose connection is to blame. You can try using a different DisplayPort cable entirely. Switch to HDMI and see if you’re experiencing the same issue. Switch back, and make sure your monitor has correctly selected DisplayPort as its connection —I suspect it has, but it never hurts to check.

You can try resetting your monitor’s settings using the aforementioned “All Reset” command. That might not solve the issue, but, again, it’s an idea. You can also try resetting your motherboard’s settings to their factory defaults via your BIOS. You can power down your system, pop out the CMOS battery, wait a few minutes, and pop it back in, just in case there’s some quirky setting that’s causing these issues.

If you’re still having issues, you can go one step deeper: Reseat your graphics card (take it out and plug it back in). Unplug any power cables going to your graphics card and plug them back in. Reseat your RAM. Unplug the power cables going to your motherboard (the fat 24-pin connector and the tinier 4- or 8-pin connector) and plug them back in.

I’m struggling to think of anything else you can do at this point, but my gut feeling is that the DisplayPort Deep Sleep setting is to blame for your issues. This is a brand-new PC, after all. While faulty hardware can strike at any time, I don’t think that’s the issue here. I think this annoying setting is what’s giving you grief.

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