Internet, Networking, & Security Home Networking How to Check for Disconnected Monitor Power Cable Connections Monitor won't turn on? Try this By Tim Fisher General Manager, VP, Lifewire.com Tim Fisher has 30+ years' professional technology support experience. He writes troubleshooting content and is the General Manager of Lifewire. our editorial process Facebook Twitter LinkedIn Tim Fisher Updated March 17, 2020 Home Networking The Wireless Connection Routers & Firewalls Network Hubs ISP Broadband Ethernet Installing & Upgrading Wi-Fi & Wireless Tweet Share Email Power cables sometimes wiggle loose from monitors over time or after being moved around. Checking every point where electricity is delivered to the monitor is usually an early troubleshooting step when a monitor is blank. 01 of 03 Check the Power Cable Behind the Monitor Power Cable Connection Behind Monitor. The power cable connected to the monitor should fit firmly in the three-pronged port on the back of the monitor. This power cable is usually of the exact same type as the power cable to the computer case but may be a different color. The monitor you see in this picture has an HDMI cable plugged in on the right; the power cable is located on the left in this picture. Make sure you power off the monitor, using the power button on the front of the monitor, before securing the power cable into the back of the monitor. If the monitor is powered on and the other end of the power cable is plugged into a working outlet, you run the risk of electric shock. Some older styles of monitors have power cables that are "hard wired" directly to the monitor. These cables do not typically come loose. If you suspect an issue with this type of power connection, keep your personal safety in mind and don't service the monitor yourself; replace it or seek help from a computer repair service. 02 of 03 Verify Monitor Power Cables Are Securely Plugged In Power Cable Connections on Power Strip. Follow the power cable from the back of the monitor to the wall outlet, surge protector, power strip, or battery backup that it is (or should be) plugged in to. Make sure the power cable is securely plugged in. 03 of 03 Verify Power Strip or Surge Protector Is Securely Plugged Into a Wall Outlet Power Cable Connection on Wall Outlet. If the power cable from the monitor was plugged into the wall outlet in the last step, your verification is already complete. If your power cable is instead plugged into a surge protector, UPS, etc., ensure that particular device is securely plugged into the wall outlet.