[SOLVED] Monitor backlight keeps coming on when pc is turned off

[Aravind92]

So, I built the pc in dec 2019, got a lg monitor first, had to replace that twice due to dead pixels and another issue, then got an acer vg240yp, this also I had to replace the very next day cause dead pixels on the first piece.
Anyway, ever since I got this monitor, I can't seem to keep it in standby, always when the pc is turned off, the backlight keeps coming on, even removing the power cord from my pc's power supply does not solve this, I have to either turn the monitor off or remove the dp cable. Have tried different dp ports on the gpu.
Anyone seen something like this, its very annoying, every few seconds it comes on like this, but the led on the monitor is still amber for stand-by.
Also, it seems to be less frequent if I unplugged the dp cable for a while and plug it back in.
https://iili.io/K50rcg.jpg
What could be the cause, I don't have another dp cable on hand.
Monitor is absolutely fine when using the pc though. This happens even if the pc is sleeping.

 

[QwerkyPengwen]

I would say double check the power mode options in the monitor's built in settings and ensure that something isn't amiss.
Otherwise, it could be faulty hardware or firmware that makes it think it's getting some kind of signal or something that makes it wake up the display.

I've personally used Dell monitors for the longest time and have never once had an issue with them ranging from low end budget monitors up to high end options with G-Sync and whatnot.

Maybe you have bad luck as well

 

[Aravind92]

I would say double check the power mode options in the monitor's built in settings and ensure that something isn't amiss.
Otherwise, it could be faulty hardware or firmware that makes it think it's getting some kind of signal or something that makes it wake up the display.

I've personally used Dell monitors for the longest time and have never once had an issue with them ranging from low end budget monitors up to high end options with G-Sync and whatnot.

Maybe you have bad luck as well

Oh I have bad luck, alright, this is the 4th montior on this pc, its insane, two had deadpixels, another piece had a gap between the bezel and screen, this one also developed a dead pixel after 9 months of use, it is the tiniest though, can't really find it even if I look for it, takes a little while to locate eventhough I know where it is.

Anyway, I've already reset the monitor to factory default multiple times, so not an issue with settings I guess. I've gone through all the settings to find something related, no luck there.

Could it just be the cable? I can't find anything like this even online, this montior has done it from the time I bought it, didn't bother taking it back to the store again, It was already the 4th one and without deadpixel at the time, I figured this is the best I was going to get.

 

[QwerkyPengwen]

so... you haven't tested it with nothing but power cable plugged into the monitor to see if it just lights up again?
And as I said, firmware could be borked, could be bad hardware inside where you plug the video cable in at, could be something else even.
Try a different cable if you want. probably won't do anything though.

My suggestion if a different cable doesn't work, take it back if you still can and get a Dell monitor.
Or get your money back entirely, then go online and get something for a good price.
Use PCPartPicker to help you find a decent monitor.

 

[Aravind92]

No, it doesn't do it when the dp cable is removed, that is the only fix that has worked, remove dp, cable keep monitor powered on, its all fine. However, leaving the dp cable connected and removing the source of power for the dp cable, psu power cord, the issue persists.

Can't return the Monitor now unfortunately, store won't take it back. I live in India btw, so no pcpartpicker either, also there aren't too many gaming monitor choices here for 1080p, this is the best one, both Asus and comparable AOC models not for sale here.

Well, I am going to get another DP cable and see how it goes, that was my plan all along, just wanted to check if someone's seen anything similar here.

 

[QwerkyPengwen]

alright then, try disconnecting the DP cable from the PC so it's just only connected to the monitor and disconnected on the other end.
Does the issue persist?
If so, try a different cable.
I assume the monitor has only one DP port on it, if it has more than one, try a different port, otherwise definitely try a different cable.
Perhaps try an HDMI cable as well if the monitor supports HDMI (again, disconnected on the other end) and see if the issue persists with HDMI as well.

 

[Aravind92]

Alright, removing the dp cable from the pc or the monitor solves the issue. However, a curious development, I started unpluggin all the other cables from the pc apart from the dp to see if something else was causing it as even removing the power cord from the psu didn't help, guess what, I unplussged everything and just left the ethernet cable and the dp cable connected, the monitor still kept doing it, but once I removed the ethernet cable, it stopped.

What is happening, is the ether cable waking my monitor, curiously, even removing the ethernet cable from the router doesn't help, only removing it from the pc solves the issue.

 

[Aravind92]

Just unchecked the "allow this device to wake my computer", seems to have stopped, can't be sure, must wait and observe, but if this solves it, I dunno, how could this affect when the pc is turned off.

 

[QwerkyPengwen]

Unplugging your PC doesn't remove any residual electricity left inside the PSU and components.
When you have the options enabled in BIOS to allow the PC the be awakened via network and other things that can cause an issue with stuff yes, although, it causing issues to this degree with everything unplugged is something I've never experienced.

Turning those settings off sounds like it did fix the issue. Guess we'll have to wait and see though.

 

[Aravind92]

Unplugging your PC doesn't remove any residual electricity left inside the PSU and components.
When you have the options enabled in BIOS to allow the PC the be awakened via network and other things that can cause an issue with stuff yes, although, it causing issues to this degree with everything unplugged is something I've never experienced.

Turning those settings off sounds like it did fix the issue. Guess we'll have to wait and see though.

I held the power button on the pc after unplugging the power cord to power drain, it still happened, maybe that is not enough, Anyway, the option I mentioned is not withing the BIOS, it is under device manager in Windows for network adapter. That is what is confusing for me, how a windows setting changes behaviour when the pc is turned off, I even have the fast start up option disabled under powe options in Windows 10. But, the network adapter setting seems to have done the trick. Will keep observing though.

 

[Aravind92]

So, that wasn't it, back to sqaure one now, only unplugging the dp cable from one end, either the pc or monitor fixes this. It seemed fine for a day after the network adapter change, although less frequent it happened again. Ordering a DP cable now, I will update the post.