Only one monitor displays on bootup

[FireMarshalBill69]

I have been using my two monitors for ages. I happen to turn the PC off nightly. But since recently, AT RANDOM, my main monitor does not display anything, but the right one will. If I reboot, all is well. But, only once in a while this happens. So far, every time, it has been the left monitor that has done this. Never the right one. The puzzling thing is that the second time I reboot, everything is okay for the entire session, meaning this happens only on bootup. Using Windows 10, 22H2. And, I am up-to-date on all updates. The drivers are up-to-date. All is well in the Display settings.

 

[ChatGPT]

Ah, the classic "Why is my monitor gaslighting me?" scenario.
What's happening here sounds like the left monitor's connection is potentially having a handshake issue during boot-up, where it's not being properly initialized at the BIOS or Windows startup. A few culprits come to mind; let's troubleshoot like pros:

1. Port/Connection Jitters​

• Cable Check: Start with the basics. Inspect the cable connecting your main monitor (the left one) for loose connections, kinked wires, or wear. Even if it's seemingly fine during regular use, boot-up initializes displays differently, which could expose a weak link (pun intended). If you're using HDMI/DP, try swapping the cable and see if the issue occurs again.
• Port Change-Up: Disconnect your main monitor and connect it to a different port on the GPU (Graphics Card). This can help determine if the port is causing the problem.
• Switch Monitors: If your monitors are interchangeable, physically swap the ports they are connected to. This will indicate whether the problem is related to the monitor, cable, or port.

2. Power Delivery Shenanigans​

• Is the left monitor powered on in time during boot? Some monitors (especially older ones or cheaper models) might take slightly longer to "wake up" when the PC powers on, resulting in the issue you're describing.
• Try turning off both monitors entirely, then powering them on after the PC has started booting.

3. Driver Mischief​

• I know you said your drivers are updated, but Display and GPU drivers can have quirks. Use DDU (Display Driver Uninstaller) to reinstall your graphics drivers from scratch. Sometimes updates leave behind old profiles that cause issues.
• Here's the link for DDU: https://www.wagnardsoft.com/ (Safe and widely used).

4. Windows Boot Sequence Is Too Cool for School​

• BIOS/UEFI Configs: Sometimes the integrated graphics or motherboard takes precedence over the GPU during the boot sequence. Check your BIOS/UEFI settings to ensure the GPU is set as the primary display adapter. Look for an option like "Primary Display Output" or "PEG/GPU" and set it to prioritize your discrete GPU.
• Windows Default Monitor Issue: The left monitor might not be considered your "main" display at boot. Go to Settings → System → Display, select the problematic left monitor, and verify if "Make this my main display" is checked.

5. Hardware Sneakiness​

• Failing Capacitors: If this happens only with the left monitor, it could indicate a power delivery problem or capacitor failure in the monitor circuitry. If available, test this monitor on a separate system to rule that out.
• GPU Teasing You?: Stress test the GPU using software like FurMark or 3DMark. If it behaves erratically or struggles under load, it could reveal issues that tie into your boot display problems.

6. Fast Boot Setting​

• Windows 10 uses a "Fast Startup" feature to make the boot process quicker, but this can sometimes mess with display initialization. Disable it to see if it solves the issue:
• Open Control Panel.
• Navigate to Power Options → Choose what the power button does.
• Click "Change settings that are currently unavailable."
• Uncheck "Turn on fast startup."
• Save changes and reboot.

7. Ghosts of Updates Past​

• A recent Windows Update could also be doing its usual meddling. As a troubleshooting step, you might consider rolling back updates (if any installed prior to this issue).

8. Specific Bootup Configuration​

• Check Event Viewer for strange errors during boot-up:
• Press Win + X and select Event Viewer.
• Check Windows Logs → System.
• Look for time-stamped warnings/errors that coincide with the display initialization issue.
• Sometimes, this could give a clue (e.g., a particular display or graphics device taking longer to initialize).

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The Sherlock Plan:

• Begin with the cable/connection swap experiment.
• Disable Fast Boot.
• Reset/reinstall display drivers with DDU.
• Test for hardware and boot sequence issues.

Once you've gone through a few of these, let me know how it turns out! Or if you'd like, I can hold a séance for your monitor, in case it was haunted all along.