Windows no longer recognizes the second monitor.
Windows no longer recognizes the second monitor.
Initially, this might be related to Windows 11 or graphics driver problems. I wasn't sure whether to submit this to Graphics, Displays, or Windows 11.
About four hours ago, my second monitor ceased functioning. I’m generally quite skilled with computers, and neither I nor my IT-savvy friend could resolve the issue. Over the past few days, I’ve been trying to connect my desktop to a second screen using an HDMI to VGA adapter (which supports EDID info) and a connected monitor.
Today, upon returning home and connecting my monitor, it failed to detect any video signal or power up. I’m running a Lenovo ThinkPad T15p with Windows 11 (fully installed by OEM) and Intel UHD Graphics. I went through Display Settings to turn it on, but it still didn’t appear. After unplugging and plugging it back in, the problem persisted. When I pressed the display detection button, nothing showed up either.
At this stage, I suspect the adapter may have failed. I then connected it to my Xbox 360—the only other device with an HDMI output. The monitor turned on immediately when I powered on the Xbox and displayed correctly. I checked the laptop’s HDMI port for any damage, but everything looked intact.
I then tried connecting the laptop to my TV’s HDMI port; it recognized the TV and functioned properly. This indicates the adapter cable and laptop’s HDMI port are in good condition. I restarted my computer in hopes of a temporary driver glitch. Still nothing. I rebooted again, adjusted UEFI settings to prioritize video output on the HDMI port, and upon restarting, the second monitor powered on and displayed the boot screen.
Once Windows login appeared, the second monitor shut down and the login screen moved to the first monitor. After logging in, checking settings, it remained undetected. I’m now convinced my drivers are faulty. I spent a considerable time uninstalling, reinstalling, and testing various driver versions and Intel Graphics controls, relaunching Settings repeatedly, but nothing worked.
Once more, I consulted a friend who connected the monitor to his computer via the same adapter (using an HDMI to VGA converter). The monitor turned on instantly and operated normally, just like with my own setup until recently. He left, and I kept trying different solutions online—all pointing to the same unresolved problem.
Additionally, the monitor didn’t appear in Device Manager at all, not even as a malfunctioning or unrecognized device.
Look in Reliability History/Monitor and Event Viewer for any error codes, warnings, or event informational events that occurred just before or at the time(s) that the monitor stopped working.
And I am also wondering about that $7 adapter....
If possible try some other tests that do not include the adapter.
Thank you. I plan to do that today. The adapter functioned well on a friend’s PC and with my Xbox 360, though I may consider swapping it out. Right now I only have my laptop and Xbox, both featuring HDMI ports.