I'm trying to add an older VGA monitor as a second display for schoolwork. The monitor itself works, and I have a VGA-to-DisplayPort cable, but my computer doesn't detect the monitor. My main monitor works normally. What could be causing this, and do I need a different type of adapter?
2 Answers
Try narrowing it down with another cable or adapter, and test the monitor on a different computer if possible. The old monitor, the graphics card or motherboard port, or the adapter itself could be faulty. A monitor that’s around 20 years old may also have compatibility or hardware problems.
DisplayPort and VGA adapters are directional, so the adapter has to match the signal’s direction. Since the computer outputs DisplayPort and the monitor accepts VGA, you need a DisplayPort-to-VGA adapter or cable—not a VGA-to-DisplayPort one. Because VGA is analog and DisplayPort is digital, make sure it’s an active adapter if required.
My monitor only has a VGA input, so I’ll double-check that the adapter is specifically made for DisplayPort output to VGA input.
It may just be the age of the monitor, but I’ll test it with another adapter before assuming it has failed.