Solved Displayport Monitor not being recognized at Startup - Sometimes

I have a LG 27GL850 Monitor that I connect to the PC using a Displayport cable. Everything work fine, except:

I have to remember to turn the monitor on before I startup (boot) the PC. If the PC passes the POST and the monitor is not up and running then neither the BIOS or Windows can use the monitor. I have to reset the PC in order to get the monitor working. (This never was the case with my monitors hooked up with HDMI).

Turning the monitor off and back on again does nothing.
Unplugging and replugging the DP cable does nothing.
The monitor remains black.

I could leave the monitor in low power standby, but I'd like to know what's going on and correct the problem if possible.
Any ideas?

At a guess, if the PC can’t detect a monitor at boot, there’s a problem; This is where standby mode is important, it needs the power standby to say “Hey, we have contact”.

I think it’s normal behaviour for a Displayport connection that the monitor must be on when you boot the computer for windows to recognise an active Displayport and send a signal. When you turn off the monitor Windows disables Displayport until you reboot. I think…
Otherwise you’d have to try detect it in Display settings after turning it on? I’d sooner keep low power standby on for boot detection.

I tried and found that It doesn´t happen in my case, Lenovo desktop and Dell monitor connected by DP. The monitor works if I turn it on after the POST. Normally I don´t do this, I leave the monitor in standby mode.

Try this: NVIDIA Support

antspants said:

At a guess, if the PC can’t detect a monitor at boot, there’s a problem; This is where standby mode is important, it needs the power standby to say “Hey, we have contact”.

I think it’s normal behaviour for a Displayport connection that the monitor must be on when you boot the computer for windows to recognise an active Displayport and send a signal. When you turn off the monitor Windows disables Displayport until you reboot. I think…
Otherwise you’d have to try detect it in Display settings after turning it on? I’d sooner keep low power standby on for boot detection.

Click to expand...

Yeah, that's the funny thing - It's hard to get to settings when you don't have a monitor!
Low power standby is workaround.

BamaInArk said:

Try this: NVIDIA Support

Click to expand...

I'm not sure that applies to my symptoms.

"Without the update, systems that are connected to a DisplayPort monitor using DisplayID could experience blank screens on boot until the OS loads. This update should only be applied if blank screens are occurring on boot."

My monitor stays black even after Windows loads.

Anibor_11 said:

I tried and found that It doesn´t happen in my case, Lenovo desktop and Dell monitor connected by DP. The monitor works if I turn it on after the POST. Normally I don´t do this, I leave the monitor in standby mode.

Click to expand...

That is helpful. It means that it is probably not the Displayport connection itself. I'm wondering if it could be the monitor or it's settings.

TVeblen said:

Yeah, that's the funny thing - It's hard to get to settings when you don't have a monitor!
Low power standby is workaround.

Click to expand...

Are there any updates for your BIOS? Not that it mentions that there is a Displayport adjustment, are you running either of these?

PRO Z790-A WIFI
Stable
AMI BIOS 7E07vA920 24-01-19

Or beta
AMI BIOS 7E07vAA1(Beta version) 2024-02-22

I am on 7E07vA8
There may be a newer one now but I haven't checked.

Ah. I see those now.
I will do an update this weekend.

@TVeblen


I had a similar problem with an EVGA 2070 vid card.
In my case it turned out to be "which" display port connector on the vid card, I had connected to my DELL monitor.




EVGA premium tech support explained that the vid card BIOS was coded to give priority to certain connectors on the vid card.
On my vid card... HDMI had the highest priority. So when I booted the computer, the LG TV (hooked up via HDMI) acted as the primary monitor, no matter whether I set the DELL to primary or not. This occurred whether the LG TV was powered on or not.

When I explained the problem to EVGA premium support... the guy said... turn on the TV. I did, and lo and behold, there was my "screen", functioning as it should be.

The solution in my case was to connect the DELL (via display port) to the connector shown with the GREEN dot.
After doing that, the DELL (set to be the primary), obeyed the Nvidia control panel setting, and all was well.
You'll have to try each of your vid card display port connectors, to see if one of them... solves the problem.

In other words, that Nvidia firmware update "may" solve your problem.
I would try the different vid card display port connectors, looking for the one that allows your LG monitor to... come on, whether it's powered on or not.

Side note... the date on the NVIDIA GPU Firmware Update Tool, is about a year after I had the problem.
This seems about right. It could easily take that long to prove the problem exists, and to then code a solution.

Flashing the vid card BIOS is dangerous. So exhaust all other options, first.

I'll try the different ports. Can't hurt!

This is my card (MSI GTX 3060 Ventus)


No indications on the card.

I'll try the firmware too. I just have limited time to do so until the weekend.

Also, I just had a look, all 4 out of 6 of my monitors using DP’s come to life after turning them back on after boot. I also variated Displayport inputs, it had no impact. I have 3 DP’s on my card, one on my Motherboard.The other 2 are using HDMI
This makes my original post redundant I suppose.

TVeblen said:

I'll try the different ports. Can't hurt!

This is my card (MSI GTX 3060 Ventus)
View attachment 89395

No indications on the card.

Click to expand...

There's no indicators on MY card either. I put those dots on a pic of my vid card... with an image editor.
I did that, just to make it easier to explain.
You have to TRY the various display port connectors on the vid card. Do this BEFORE you attempt the vid card BIOS update.



Summary...

1. With the LG TV hdmi cable removed from the vid card, all display port connectors work fine.
2. With the LG TV hdmi cable hooked to the vid card, only the display port with the GREEN dot, functions normally.
3. With the LG TV hdmi cable hooked to the vid card, the BLUE dot display port connectors, only function properly for a secondary display. AND, they may indeed, have the same problem you are having.

The "point" of all this... is that the vid card BIOS is coded to give certain vid card connectors... priority.
YOU have to figure out which is the "correct" display port connector to use for your LG monitor.

I say again...

Flashing the vid card BIOS is dangerous. So exhaust all other options, first.

It more dangerous than flashing the motherboard BIOS, because Windows will be running when you do it. !!!!
And if Win 11 has taught us anything, it's that Windows can do whatever it wants... whenever it wants. ^^

And if the vid card BIOS flash fails... you "might" have bricked the vid card. !!

Now if you have lots of money to burn... then no worries. But vid cards aren't cheap.



============================================================================





Really short version...
Never flash a vid card BIOS unless you have lots of money AND have already tried everything else.

Understood.
And couldn't agree more.

It seems like this is a simple error. One that should be correctable in a BIOS or monitor setting.
It's like if the monitor is not detected at post - and I have been just quick enough to get it on after starting the PC - then it does not exist to the system. It's a matter of a second early or a second late makes the difference.

An update
It seems to be working now (after one test boot).

Unfortunately I broke my own rule and did 3 system changes before testing - so it will be hard to determine which thing did it.

I updated to BIOS A9
I updated my Nvidia graphics driver to v551.76
I enabled G-Sync in the Nvidia Control Panel for my G-Sync compatible monitor.

I will update again after a few more days (tests)