OS: Windows 10 Home, 64bit; CPU: Intel Core i5 25003.30GHz; RAM: 32G; Monitors: - HP ProDisplay P221 LED Backlit Monitor, DVI-D connection - Dell U3415W, HDMI connection; Graphics Card: NVIDIA GeForce GTX 970
Problem: Upgraded the existing Windows 7 to Windows 10. Both monitors worked fine for months. Over the last month, the Dell U3415W monitor goes into standby mode after my PC goes into sleep mode. The display setting no longer sees the Dell monitor. Doesn't matter if it's the primary or secondary monitor. When it first happened, I rolled back the driver for the graphics card. Did not resolve the issue. Did all of the usual other tasks that I would recommend initially.
Updated the most current NVIDIA driver, version 220.127.116.1141. Went to display settings to see if it would detect the second monitor as a routine check (didn't). Scanned for new hardware (still undetected). Looked in device manager to see if this might have reverted to an "unknown" device. None listed. Checked the physical connection to make sure it wasn't loose. It's not.
I can turn off the monitor and power it back on. There is a 50/50 chance the monitor will be detected. If not, I have to reboot. Or I can disable the graphics card and then re-enable it and will usual detect it.
When cycling the power on the monitor, the Dell monitor remains black. However, I know the PC recognizes the monitor is there as I am able to move my mouse cursor across to the Dell monitor. Some applications that are open move from the HP monitor to the Dell monitor. The Dell monitor remains black and I'm unable to see any of the apps. Monitor still shows in standby mode. I turn off the Dell monitor and all of my apps move back to my HP monitor as it becomes the only monitor.
I want to find a solution so I am not having to manipulate my system to get my second monitor to show up. The other posts don't deal with intermittent detection issues.
Would appreciate it if someone knew the resolution or could provide additional troubleshooting steps.