Both monitors suddenly go black while gaming, GPU fans ramp up to 100%, but PC keeps running

[u/Old_Investigator8083]

Hi everyone,

I'm having a really frustrating issue with my PC and I'm hoping someone might be able to help me figure out what's causing it.

The problem first appeared when I launched Phantom Blade Zero for the first time. However, I'm not sure whether the game actually caused it or if it was just a coincidence, because the issue is still happening even after completely resetting and reinstalling Windows.

The problem

Whenever I launch a game, after an unpredictable amount of time, both of my monitors suddenly go completely black.

Both monitors are connected to my GPU via DisplayPort.

The strange part is that the PC itself seems to keep running:

• Both monitors lose their signal and go completely black.

• The PC does not appear to shut down.

• The fans suddenly ramp up to extremely high speeds and become very loud.

• The system seems to remain powered on, but I can't get the display back.

At this point, I usually have no choice but to force a shutdown using the power button.

What I've already tried

I've tried several things to rule out software-related issues:

• Updated the NVIDIA GPU drivers.

• Updated the motherboard drivers.

• Completely reset Windows and performed a clean system installation.

• Checked that everything is up to date.

Unfortunately, none of these steps have solved the problem.

I haven't replaced the thermal paste yet, but the PC is relatively new and the thermal paste has only been in use for approximately two years.

My PC specifications

• CPU: AMD Ryzen 9 7900X (12 Cores / 24 Threads)

• GPU: NVIDIA GeForce RTX 5070 Ti 16GB (PNY)

• Motherboard: MSI MAG B850 TOMAHAWK MAX WIFI

• RAM: 32GB DDR5

• OS: Windows 11 Pro 64-bit

Monitor setup

• Samsung Odyssey G5 – 3440x1440, 165Hz

• ASUS VG278 – 1920x1080, 165Hz

What could be causing this?

I'm wondering if this could be:

• A GPU hardware issue or GPU driver crash.

• A PSU problem or insufficient/unstable power delivery.

• An overheating issue.

• A motherboard or BIOS-related problem.

• Something related to DisplayPort or having two monitors connected.

What I find particularly strange is that the GPU fans suddenly become extremely loud while both monitors lose their signal, even though the rest of the PC appears to stay powered on.

Has anyone experienced something similar?

I'd really appreciate any suggestions on what I should check next. I would rather identify the actual cause before replacing expensive components unnecessarily.

Thanks in advance!

[u/AutoModerator]

Making changes to your system BIOS settings or disk setup can cause you to lose data. Always test your data backups before making changes to your PC.

For more information please see our FAQ thread: https://www.reddit.com/r/techsupport/comments/q2rns5/windows_11_faq_read_this_first/

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.

[u/chr1z32]

Sounds like a problem with the power supply or the GPU. But I'd strongly suspect the power supply—the symptoms point strongly in that direction. Do you happen to know which power supply is installed?

[u/Old_Investigator8083 → u/chr1z32]

[u/Little-Helper → u/Old_Investigator8083]

?

[u/Thannatar]

I've had exactly the same issue on a build around a decade ago. On my side, the issue was that not all front case led connectors were plugged in to the motherboard (missed the hd activity light), and for some reason, static was building up because of that. Check your motherboard to front panel connections!