Screen illumination during startup
Screen illumination during startup
I own a PC I assembled last October.
Hardware:
- ASUS Z890 AYW GAMING WIFI with Intel LGA 1851 ATX
- Intel Core Ultra 7 265K Arrow Lake Twenty-Core LGA 1851
- NZXT C850 850 Watt 80 Plus Gold ATX Fully Modular Power Supply
- 64GB G.Skill Trident (2 x 32GB) DDR5-6000 PC5-48000
- Two WD Black SSD drives, one 2TB and one 1TB
Operating System: Ubuntu Studio
Problem: After finishing the build, I turned it on. The screen would briefly flash for about a quarter of a second, then go black for 2–3 seconds, repeating continuously.
I brought it back to Microcenter, who immediately suggested replacing the card with the 5060 model they had. Once I installed the new card, the issue disappeared. However, once the system started up, the same flashing behavior occurred. That week it stopped working entirely and has been back to flashes since.
Today I visited Microcenter again. When they connected the KVM switch, no problems arose. The PC booted immediately without any flashing. The technician noted that the KVMs on the side of the case aren’t compatible with modern cards and recommended either bypassing them or using a newer switch.
When I returned home, I unplugged the KVM switch and connected the monitor directly. The flashing resumed. Changing HDMI cables didn’t help. Using the built-in video worked without issues (except for apps requiring the 5060 card).
What could be causing this? It seems to be related to an HDMI issue, since the technician used a DP cable. This would be problematic because my monitor only supports HDMI, not DP. I’m unsure about other possible causes.
Are there any monitors available in this model? Some monitors require their own drivers, and if you're changing them (such as with a KVM), failing to update the drivers might cause issues. Please update your post with more details about the monitors, the connections, and how the KVM switch is being used.
Are there any monitors available in this model? Some monitors require their own drivers, and if you're changing them (such as with a KVM), failing to update the drivers might cause issues. Please update your post with more details about the monitors, the connections, and how the KVM switch is being used.
It's interesting. This post made me check the monitor settings. It's an LG Ultrawide with only HDMI input. However, in the settings there was a FreeSync option. I chose to disable it. Bingo! Now it starts up immediately, without any flicker.
Occasionally, simply asking a question is enough to get an answer.