Question Dell S2721DGF black screen issue

[Insanity_]

My main monitor, a Dell S2721DGF which is a year old randomly shows a black screen with a power light and no OSD after starting up my PC or rebooting. This occurs after displaying the MSI logo and the PC POSTs. This issue started shortly after replacing my failing PSU with a Thermaltake Toughpower GF3 1200W Gold. The black screen has no backlight but the power is on. I am directly connected to an RTX 3070 with a display port cable. My secondary monitor that uses HDMI works fine. Restarting the monitor or restarting the PC fixes this issue temporarily until I turn my PC off again. This issue happens maybe in like 1 in 7 boots/reboots.


Specs:

• EVGA RTX 3070
• i7 8700k @ 3.4 GHz (4.4 GHz turboboosted)
• 32 GB of DDR4 Corsair Vengeance RAM at 3000 MHZ.
• MSI Krait Z370 gaming motherboard
• Dell S2721DGF 165HZ 1440p Monitor
• Acer GN246HL 1080p Monitor
• Thermaltake Toughpower GF3 1200 watts Gold.

I am using Display port on the main Dell monitor and HDMI for the secondary monitor, both connected to the GPU. The main monitor's power cable is connected to a UPS, secondary monitor to a power strip. The things I have tried already:

• Reinstalled display drivers using DDU
• Reseated GPU PCIe, PSU, and monitor cables
• Replaced CMOS battery
• Made sure that PSU is using two dedicated PCIe cables to the GPU.
• Changed the Display Port cable and used different display ports on the GPU.
• Reset monitor to factory settings.
• Turned off auto input on the monitor.
• Passed the self diagnostic test of disconnecting the DP cable.
• Removed all cables from the Dell monitor and held down the power button for 8 seconds.

This all started happening after I replaced my PSU with the Thermaltake, however, my PC works fine under load and none of my games crashed yet so I am not sure if it is the PSU. I was also thinking if it wasn't the cable that it might be the GPU, but similar to the PSU, my GPU works fine under load. My temps and fans are fine. I can't recreate this issue, it happens randomly around 1 in 7 times. I also notice that my lights in my room flicker when I turn my PC on, not sure if that is related. Could this possibly be a PSU issue or was this just a coincidence that this happened after I installed the PSU? I am leaning towards either a Monitor or a Port issue, but any insight would be appreciated.

 

[username-s]

Hey, I'm having a similar issue with my monitor but I don't think mine is related to the PSU and more so the monitor itself. Have you tried connecting an HDMI to the monitor? It might be an issue with the monitor not detecting DP input. If you have, maybe try connecting your PC to a computer to try to see if any input is being registered.

 

[Insanity_]

Hey, I'm having a similar issue with my monitor but I don't think mine is related to the PSU and more so the monitor itself. Have you tried connecting an HDMI to the monitor? It might be an issue with the monitor not detecting DP input. If you have, maybe try connecting your PC to a computer to try to see if any input is being registered.

Hello, I did not try HDMI but I did change the cable on my second monitor to HDMI instead of DVI and the issue randomly went away after hard resetting my DELL monitor. I am not sure which fixed it or why but I agree with you that it isn't a PSU issue. This problem can possibly come back but it definitely seems to be an issue with the monitor as I have seen multiple reports in different forums about the same exact issue with this specific monitor. Do you have a second monitor attached? Every post regarding this issue appears to be a multi-monitor setup which may be a contributing factor to this display issue.

 

[username-s]

Hello, I did not try HDMI but I did change the cable on my second monitor to HDMI instead of DVI and the issue randomly went away after hard resetting my DELL monitor. I am not sure which fixed it or why but I agree with you that it isn't a PSU issue. This problem can possibly come back but it definitely seems to be an issue with the monitor as I have seen multiple reports in different forums about the same exact issue with this specific monitor. Do you have a second monitor attached? Every post regarding this issue appears to be a multi-monitor setup which may be a contributing factor to this display issue.

I looked through a bunch of other people's post too scouring the internet and most of them were either issues with multiple monitors or their laptops connected to a monitor. A bunch also found a fix by switching from DP to HDMI, which is something related to the monitor I believe.

I have a single monitor setup. My monitor is a Dell 2721HGF. The monitor would not detect my PCs iGPU, can't boot to BIOS, and it would detect mac input depending on its mood I guess. Switching the cable didn't do anything for me, the only fix (to enter BIOS) was to connect to a different monitor first on boot and then switch to the Dell monitor after.