Monitor disconnects from DisplayPort when going into Power Save mode

[Sawtaytoes]

I have an LG 38GN950-B. I haven't seen anyone specifically report issues on this model of display, but when the monitor goes into power save, after 3-5 minutes, it will disconnect from DisplayPort. It also turns off all the USB ports, but that happens regardless of the DisplayPort connection issue.

 

When I got this monitor, I had 6 monitors already, but got rid of one to make this fit. I still have 6 monitors, and the only difference from before is that this is now my primary display.

 

My Setup

• ASUS ROG Crossfire VIII Hero
• AMD Ryzen R9 5950X
• nVIDIA GeForce RTX 3090 (for driving my ultrawide monitors and a VR headset)
• nVIDIA GeForce GTX 970 (for driving other monitors)

The monitor is plugged into the furthest DisplayPort on the 3090. The 970 is in the bottom-most 16x slot on this board which only runs at 4x. That means my 3090 has the full PCIe 16x bandwidth available.

 

Things I've Tried

1. Exchanging the monitor for a brand new one.
2. Swapped the existing Monoprice DisplayPort cable for a QVS one from Micro Center one.
3. Used the DisplayPort cable that came in the box.
4. Changing the refresh rate between from 160Hz to 120Hz, and then to 60Hz.
5. Swapped the existing ASUS TUF 3090 for an ASUS ROG STRIX 3090.
6. Turned off G-Sync.
7. Resetting the monitor settings, disabling overclocking, disabling every power save and eco setting, etc.
8. Using a different color profile in Windows.

What worked

When using my Surface Pro 6 tablet with a miniDP to DP adapter and the same cable model of cable, it works fine. It's possible this adapter is doing something though. Also, the tablet is using Intel graphics, not nVIDIA. This may be the issue.

 

Help me

Does anyone know what might be going on? Maybe something I could do to fix it or at least figure out what's wrong? I've been going back and forth with LG support wasting many hours of my time trying to figure this out.

 

I'd replace the monitor with another brand, but the only other 3840x1600 monitor not made by LG is the Alienware AW3821 (using the same panel). Sadly, you can't disable the local backlight dimming on that display, and reviews say the backlight dimming is really bad.

 

I've thought about getting a 4K replacement, but the only suitable one that matches this width would be a 40" 4K@120Hz curved monitor w/ HDR (if one exists), and it'd have to support HDMI 2.1. At a previous job, they bought me a Philips BDM4037UW which, while only 60Hz, was the perfect size. Philips doesn't manufacture it anymore, and it doesn't fit my needs for a primary display. From looking around, literally no manufacturers have a 40" curved display. They have some 43" models, but they're not curved .

 

Other Reports Online

Many people have been seeing these issues with the 27" model, but not the 38" model. I'm assuming that's because I'm in the minority and that most people who own this display aren't using multiple monitors. Just a guess.

• Amazon review of the LG 27GN880-B.
• Reddit thread on the LG 27GN950-B.
• Reddit thread on two LG 27GN880-B.
• AMD thread on the LG 27GL83A-B.
• LTT thread on an unlisted monitor.
• ArsTechnica thread on unlisted LG monitor.
• Apple Discussions thread on unlisted LG 5K monitor.
• nVIDIA thread on Acer XB270HU and Acer CB270HU monitors. Others note issues with the AOC 2460PF, ASUS PG279Q, ASUS VG279QM, Alienware AW3418DW, and many others, but this thread is 6 years old. It looks like it was a driver issue. This is also the only non-LG disconnect thread I've seen.

[Stahlmann]

I have had the same problem with a Philips monitor for a few months now. In the end it doesn't bother me that much as i stopped using screen savers or auto-power saving mode. I generally turn off my computer when i go watch TV or do something else. As it only needs 20 seconds from pressing the power button, entering my PIN, to browsing YouTube i don't really care.

 

Could be something wrong with Windows power saving mode, not neccesarily your monitor or GPU. Windows is known by now to have it's weird quirks. Then again, it also happens with MacOS...

[Kamikater]

Hi,

 

I experience the same behavior, however my setup is different in almost every aspect (I use two BenQ monitors, one is connected via HDMI, the other via Display Port, I use Linux Mint with XFCE, and use no graphics card). The only thing that's the same is that I too use an AMD Ryzen (5600G). This also happens when I turn off the HDMI Monitor (but not when I connect one via D-Sub).

 

I experience this behavior also with Linux that I run from freshly flashed USB sticks, so it's not a setting I accidentally made in the OS itself.

 

So I suspect that this behavior is some sort of new "feature". Maybe by AMD, maybe not (I didn't have this behavior on my previous computer that ran off an Intel processor, so there's that). Maybe it's some weird BIOS/UEFI setting we are missing?

 

It's highly annoying to say the least.

[ssjfajitas]

So I needed to create an account to add my bit on this issue.

 

I recently bought two of the LG 27GL83A , (27" 1440p IPS 144hz) to go with my 3070ti but encountered virtually the same issue here:

The screen goes into power save mode in 2 ways that I'm aware of:

1) lock screen - after about 2 minutes by default on Windows.

2) power settings configured to put monitors into power save mode after a set time has lapsed.

Through troubleshooting on my end I can say it does not occur after restart/shut downs, only so far the power save mode.

 

After a few minutes when the monitors went into this standby mode I'll get an audio alert for device connect/disconnect and will typically happen once again when I move my mouse to wake the monitors up from this mode. I know this device is the display device because my task bar keeps resetting. 

 

I ended up doing the following, all of which have not resolved the issue:

 

-Reinstalled drivers via DDU

-Tested HDMI port and all DP ports

-Purchased two new DP cables rated 1.4

-Upgraded my PSU from 750w to 1200w, thinking it might be a power draw issue.

-Disabled any power save options that were useful for just battery devices.

-Turned off energy saver mode and other standby modes in both monitor settings

-sfc /scannow

-Reinstalled Windows

 

I think it's this specific brand of monitors because when I try just one of my monitors, issue persists, but when I connect to an older ASUS 24" the issue clears up completely.... So tomorrow I'm going to go to microcenter and see if they have an equal monitor with ASUS or ACER or something to determine once and for all. 

 

If the new monitor brand has the same issue I fear it might be a GPU or MOBO fault. We'll see, I'm still within the 30 days for all of it.

 

I'll update my results then, but I have to say researching while troubleshooting for this wasn't very easy, hats off to you for creating such a detailed thread, this is def a community I want to be apart of now.

[Glenwing]

Just to be clear, this isn't a bug or glitch, so no amount of scanning or replacements is going to help. This is a consequence of how DisplayPort is designed, so most DisplayPort monitors will behave this way. If you don't want this behavior, don't use DisplayPort.

 

DVI and HDMI provide a small 5 V power line from the source to the display. This provides a minimal amount of power to the display so that its identification data can be read. Since this power is provided by the source device, it does not depend on the power or state of the display. Even if the display is completely unplugged from the wall, the source will be able to read it and see that a display is attached.

 

https://www.extron.com/download/files/articles/understandingedid.pdf

Quote

The DDC specifications define a +5V supply connection for the source to provide power to a display's EDID circuitry so that communication can be enabled, even if the display is powered off.

This is of course a sort of "optional" behavior, so an HDMI device can always be programmed to refuse to send EDID data unless it is in the powered-on state, so you will note some TVs will do this and therefore will exhibit the same behavior, where they "disconnect" when turned off. But most HDMI monitors will allow EDID reading regardless of whether they are on or off, so they won't have the issue.

 

DisplayPort is designed differently. It does not provide any power from source to sink. Therefore, when the display is powered off, its EDID cannot be read and the display will no longer be recognized. It is that simple, and any DisplayPort connection will be subject to this.

 

However, some people may note that they have a monitor that doesn't exhibit this behavior when using DisplayPort; the display stays recognized in the OS even after the monitor is turned off using the power button. I have a few of them (Dell S2417DG if power-saving mode is off, LG 27GL850 first revision only). In these cases, the monitor is basically not really turning off when you press the power button. It shuts off the LCD and backlight and may also go into a lower power state, but it still keeps the display controller running, and is therefore still able to respond to EDID read requests.

 

You can even test this by unplugging the monitor from power; this will cause it to disconnect from the OS just like any other DisplayPort connection. So whether this "disconnect" behavior exists will depends on how manufacturers implement power-off mode and power button functionality, and just how "off" the display goes when you press the button. If the manufacturer implements a soft power-off, then it may be ok. Unfortunately the vast majority of monitors go into a fairly deep power off state and therefore will exhibit the disconnect behavior. This is thanks to energy-efficiency and eco initiatives. Some monitors like the Dell S2417DG allow you to choose the behavior (with the "power-save mode") toggle so they can get lower energy usage ratings while allowing the user to disable it and maintain connection while "off", but this is uncommon.

 

What we really need is for reviewers to understand this issue, start highlighting it, because right now it is really difficult to know which monitors will have the disconnect behavior and which don't. I really wish major reviewers would add a new test section where they check

1. Does the DisplayPort connection disconnect when the power button is pressed.
2. Are there any menu options that affect this behavior (usually labeled under power saving or eco mode)

Once reviewers start talking about it and people start asking about it, manufacturers will start responding too, I think. I suppose HDMI ports could also be subjected to the same test, since like I said, even some HDMI devices will exhibit the same behavior, though I usually only see it on some TVs.

 

By the way, I've noticed more and more people calling this the "DisplayPort hotplug issue" and now people are starting to repeat some kind of "hotplug bad" mantra. Please don't call it that. The issue has absolutely nothing to do with hotplugging. Hotplugging means the device is capable of being connected while the computer is running. If you didn't have hotplugging, you would have to shut your computer down, plug in, and then boot up again in order for the device to be recognized. All modern external connections support hotplugging. DVI and HDMI are also hotpluggable, and they don't have this issue. The issue is not related to hotplugging.

[Sawtaytoes]

Thanks for your response @Glenwing.

 

To be clear, my issue has nothing to do with the power button on the monitor. When the monitor goes into power-save, this is when it loses connection in Windows.

 

Are you saying that this occurs while the monitor is still powered on because LG failed to put +5V on one of the pins providing EDID information?

 

Might be news: I was not able to reproduce this issue using a mini DisplayPort to DisplayPort on my Surface Pro 6. It uses Intel Integrated Graphics. This might be related to nVIDIA graphics drivers + newer LG monitors.

[Glenwing]

On 4/17/2022 at 11:06 PM, Sawtaytoes said:

Thanks for your response @Glenwing.

 

To be clear, my issue has nothing to do with the power button on the monitor. When the monitor goes into power-save, this is when it loses connection in Windows.

Right, it has to do with how low-power and power-off states are handled by the monitor, which may be via the power button or auto power off.

On 4/17/2022 at 11:06 PM, Sawtaytoes said:

Are you saying that this occurs while the monitor is still powered on because LG failed to put +5V on one of the pins providing EDID information?

DisplayPort does not have a 5 V line for providing power from the source to the sink. It's not an LG-specific issue, it's a design limitation in the DisplayPort standard.

On 4/17/2022 at 11:06 PM, Sawtaytoes said:

Might be news: I was not able to reproduce this issue using a mini DisplayPort to DisplayPort on my Surface Pro 6. It uses Intel Integrated Graphics. This might be related to nVIDIA graphics drivers + newer LG monitors.

What happens if you unplug the monitor from power?

[future_knight]

On 3/22/2022 at 6:04 PM, Glenwing said:

Just to be clear, this isn't a bug or glitch, so no amount of scanning or replacements is going to help. This is a consequence of how DisplayPort is designed, so most DisplayPort monitors will behave this way. If you don't want this behavior, don't use DisplayPort.

 

DVI and HDMI provide a small 5 V power line from the source to the display. This provides a minimal amount of power to the display so that its identification data can be read. Since this power is provided by the source device, it does not depend on the power or state of the display. Even if the display is completely unplugged from the wall, the source will be able to read it and see that a display is attached.

 

https://www.extron.com/download/files/articles/understandingedid.pdf

This is of course a sort of "optional" behavior, so an HDMI device can always be programmed to refuse to send EDID data unless it is in the powered-on state, so you will note some TVs will do this and therefore will exhibit the same behavior, where they "disconnect" when turned off. But most HDMI monitors will allow EDID reading regardless of whether they are on or off, so they won't have the issue.

 

DisplayPort is designed differently. It does not provide any power from source to sink. Therefore, when the display is powered off, its EDID cannot be read and the display will no longer be recognized. It is that simple, and any DisplayPort connection will be subject to this.

 

However, some people may note that they have a monitor that doesn't exhibit this behavior when using DisplayPort; the display stays recognized in the OS even after the monitor is turned off using the power button. I have a few of them (Dell S2417DG if power-saving mode is off, LG 27GL850 first revision only). In these cases, the monitor is basically not really turning off when you press the power button. It shuts off the LCD and backlight and may also go into a lower power state, but it still keeps the display controller running, and is therefore still able to respond to EDID read requests.

 

You can even test this by unplugging the monitor from power; this will cause it to disconnect from the OS just like any other DisplayPort connection. So whether this "disconnect" behavior exists will depends on how manufacturers implement power-off mode and power button functionality, and just how "off" the display goes when you press the button. If the manufacturer implements a soft power-off, then it may be ok. Unfortunately the vast majority of monitors go into a fairly deep power off state and therefore will exhibit the disconnect behavior. This is thanks to energy-efficiency and eco initiatives. Some monitors like the Dell S2417DG allow you to choose the behavior (with the "power-save mode") toggle so they can get lower energy usage ratings while allowing the user to disable it and maintain connection while "off", but this is uncommon.

 

What we really need is for reviewers to understand this issue, start highlighting it, because right now it is really difficult to know which monitors will have the disconnect behavior and which don't. I really wish major reviewers would add a new test section where they check

1. Does the DisplayPort connection disconnect when the power button is pressed.
2. Are there any menu options that affect this behavior (usually labeled under power saving or eco mode)

Once reviewers start talking about it and people start asking about it, manufacturers will start responding too, I think. I suppose HDMI ports could also be subjected to the same test, since like I said, even some HDMI devices will exhibit the same behavior, though I usually only see it on some TVs.

 

By the way, I've noticed more and more people calling this the "DisplayPort hotplug issue" and now people are starting to repeat some kind of "hotplug bad" mantra. Please don't call it that. The issue has absolutely nothing to do with hotplugging. Hotplugging means the device is capable of being connected while the computer is running. If you didn't have hotplugging, you would habe to shut your computer down, plug in, and then boot up again in order for the device to be recognized. All modern external connections support hotplugging. DVI and HDMI are also hotpluggable, and they don't have this issue. The issue is not related to hotplugging.

 

So what are options to prevent that from happening?

Modern GPUs have mainly DisplayPort and just one HDMI slot. With a multi monitor setup you cant use all HDMI without "downgrading". HDMI isnt capable of 144 Hz like DP. So if you bought a monitor for these 144 Hz or more, you would loose that over HDMI.

 

This behavior is sooo annoying and I am looking to find a usefull solution for some time now.

[Andrewtst]

This is DP deep sleep feature and seems no way to prevent it. 

 

It is also happened to my 34" LG 34GN85 as well.

 

I had try all possible solutions found in Internet and nothing help and when wake up everything open apps is mess up and not in actual position in Windows 10. Lucky Windows 11 solved this mess up issue and I no longer care too much this issue. I think it also happen in my Samsung Odyssey Neo G9 as I heard the beep sound also when monitor go to sleep. 

 

If this is the issue bothering you and you still using Windows 10, you can use Powertoys to prevent the open apps mess up in actual open position. 

[Glenwing]

4 hours ago, future_knight said:

 

So what are options to prevent that from happening?

Modern GPUs have mainly DisplayPort and just one HDMI slot. With a multi monitor setup you cant use all HDMI without "downgrading". HDMI isnt capable of 144 Hz like DP. So if you bought a monitor for these 144 Hz or more, you would loose that over HDMI.

 

This behavior is sooo annoying and I am looking to find a usefull solution for some time now.

There aren't any that I know of, otherwise I would have mentioned them.

[Sawtaytoes]

2 hours ago, Andrewtst said:

This is DP deep sleep feature and seems no way to prevent it. 

 

It is also happened to my 34" LG 34GN85 as well.

 

I had try all possible solutions found in Internet and nothing help and when wake up everything open apps is mess up and not in actual position in Windows 10. Lucky Windows 11 solved this mess up issue and I no longer care too much this issue. I think it also happen in my Samsung Odyssey Neo G9 as I heard the beep sound also when monitor go to sleep. 

 

If this is the issue bothering you and you still using Windows 10, you can use Powertoys to prevent the open apps mess up in actual open position. 

I'm using Windows 11 now. Doesn't seem to be fixing anything even with that setting enabled:

 

On 4/18/2022 at 5:54 PM, Glenwing said:

What happens if you unplug the monitor from power?

I even tried the monitor on a KVM, same issue.

What's supposed to happen when the monitor loses power? Pretty sure Windows treats it as if the display goes away, same as if I leave it in standby-power mode from the lock screen or any sort of power-save screensaver.

Also, _just_ this monitor. I have 6 of them and only the LG experiences this issue. I tried tons of different DP1.4 cables (except an optical one), the KVM, different refresh rates, resolutions, etc. Even tried it on my work's 2019 Macbook Pro. Same issue; in fact, it often makes the Mac hard-shutdown.

 

For whatever reason, when I tried it on my Surface Pro 6 over MiniDP to DP, I wasn't able to reproduce, but maybe I just didn't wait long enough. I have a Surface Pro 8 now that I can use to test, but testing this out is super annoying since it only happens after X random minutes.

[Andrewtst]

9 minutes ago, Sawtaytoes said:

I'm using Windows 11 now. Doesn't seem to be fixing anything even with that setting enabled:

 

I even tried the monitor on a KVM, same issue.

What's supposed to happen when the monitor loses power? Pretty sure Windows treats it as if the display goes away, same as if I leave it in standby-power mode from the lock screen or any sort of power-save screensaver.

Also, _just_ this monitor. I have 6 of them and only the LG experiences this issue. I tried tons of different DP1.4 cables (except an optical one), the KVM, different refresh rates, resolutions, etc. Even tried it on my work's 2019 Macbook Pro. Same issue; in fact, it often makes the Mac hard-shutdown.

 

For whatever reason, when I tried it on my Surface Pro 6 over MiniDP to DP, I wasn't able to reproduce, but maybe I just didn't wait long enough. I have a Surface Pro 8 now that I can use to test, but testing this out is super annoying since it only happens after X random minutes.

I never have this issue since using Windows 11 even after few hours later wake from sleep. 

 

Probably you can try Microsoft PowerToys - FancyZone to more secure the apps position. 

 

For mac I not sure as I don't have mac to test out.

[Glenwing]

26 minutes ago, Sawtaytoes said:

What's supposed to happen when the monitor loses power? Pretty sure Windows treats it as if the display goes away, same as if I leave it in standby-power mode from the lock screen or any sort of power-save screensaver.

The display will no longer be detectable, Windows will register a HPD event and disconnect it.

26 minutes ago, Sawtaytoes said:

Also, _just_ this monitor. I have 6 of them and only the LG experiences this issue. I tried tons of different DP1.4 cables (except an optical one), the KVM, different refresh rates, resolutions, etc. Even tried it on my work's 2019 Macbook Pro. Same issue; in fact, it often makes the Mac hard-shutdown.

Any display connected over DisplayPort should disconnect from the OS if the monitor is unplugged from power. Some monitors connected over DisplayPort may disconnect when powered off using the monitor power button or when the monitor goes into sleep/standby mode. It depends on exactly what the monitor's power button does or how its sleep mode is implemented, which differs from model to model.

[Sawtaytoes]

On 8/15/2022 at 1:21 AM, Glenwing said:

The display will no longer be detectable, Windows will register a HPD event and disconnect it.

Any display connected over DisplayPort should disconnect from the OS if the monitor is unplugged from power. Some monitors connected over DisplayPort may disconnect when powered off using the monitor power button or when the monitor goes into sleep/standby mode. It depends on exactly what the monitor's power button does or how its sleep mode is implemented, which differs from model to model.

I see. Is there a way to fix the monitor disconnecting when it goes into standby mode?

 

Also, what's the purpose of testing the powered-off state though?

[Glenwing]

19 minutes ago, Sawtaytoes said:

I see. Is there a way to fix the monitor disconnecting when it goes into standby mode?

Not that I know of.

20 minutes ago, Sawtaytoes said:

Also, what's the purpose of testing the powered-off state though?

You mentioned that the issue stopped happening when you used Mini DP from your Surface. Since the behavior depends on the monitor, it shouldn't be affected by the cable. I wanted to check if it still disconnected when unplugged from power to check if there was anything funny going on. Some Mini DP cables are known to be wired incorrectly (providing a 3.3 V power wire where there isn't supposed to be one) so I wondered if there might be some unintended interaction happening.

[Sawtaytoes]

That makes a lot more sense now. I could try testing that sometime. The Mini DP cable I used is actually a dongle, then I used a regular DP connection. Since I'm sure this is an old no-name adapter, it's possible it's doing something funky. It's also possible I didn't wait long enough to see the issue.

[future_knight]

Is there some kind of dongle/adapter for DisplayPort I can put between my monitor and graphics card that can keep that signal alive?
This bs is really annoying me and causing actual problems when I leave it offline for longer.
I rarely shut off my main monitor anymore when I know I am not actively working on it, but IT needs to work because it cause errors when in this for longer.
I had it several times now that when I need to render or download something over night and come back in the morning: after enabling the Monitor connected with DP, Win10 is in some kind of frozen state. Lots of functions dont work anymore.
And when I try to restart, it freezes completely. I can only press my case power button until it shuts down...

Tbc, all energy options are at full power. No energy saving mode or screen standby mode that starts automatically after a certain time. These options are all disabled!

 

I really need some kind of solution for this, because I just hate it the way it is now.

 

Best regards

[<3Mortuus]

I wanna cry...
This is so bad. Why would anyone ever want this "functionality". It could even prevent you from remote connecting to your computer...

[AIucard]

I have the same issue but only with one out three monitor, in order 2 1 3,(1 is primary), all cennected with displayports, when i have windows on all three and turn off/on 2 nothing happen everything stay in place but if i do the same with 3 it act like it's disconnected, everything is moving, windows from 3 go to primary, not great, i've tried to put 3 as primary and it's the same when 1 turned off everything go to 3, only monitor 2 doesn't have issue, i've tried switching cables, hdmi, nothing help.

 

- monitor 2 is a DELL P2414H

- monitor 1 is a AOC 24G2W1G4

- monitor 3 is a DELL E2216H

 

Don't know if it can help but here it is.

[Sawtaytoes]

It happens on only my LG out of the 6 monitors on my main desktop, but also literally versus every other monitor I've owned.

Even on the same system, same cables, setup, etc, I've only had this happen with my LG Ultrawide, and only this model of LG Ultrawide.

I personally think it's a manufacturing defect, but it seems to be widespread. Even changing out the whole monitor didn't fix it, so I gave up caring. I makes me not wanna buy LG in the future though.

[NetscapeNavigator]

It had been 5 years since I had wiped Windows and it was time. I took the plunge last weekend.

 

Since then, I now have the stupid issue described in this thread. It wasn't there before so I knew I had fixed it at some point in the past. I found this reddit thread and it was the key to my success.

 

the tldr: LG probably provides a INF/driver for your monitor on their website. In my case I downloaded the driver for my monitor (32GK650F) and unzipped/installed it (right click INF file -> install). After physically disconnecting/reconnecting my monitor the problem was gone. When I disconnected/reconnected I chose a different port on my video card but I highly doubt that matters. The unplug is probably enough to get it to grab the new driver.

 

Give that a whirl if you haven't yet.

 

 

 

 

 

[Sawtaytoes]

I appreciate the link. I have the correct LG drivers for my monitor already `38GN950-B`:

 

There's a newer driver on the website for March 2023. Looks promising:

Clicking "Reference" does nothing.

 

But the download reveals this is an old driver. The download shows the same date as what I have installed: