The Basic Connection: What You Need to Know
Connecting a PC to a monitor takes about five minutes and requires only one cable. The cable runs from a port on the back of your computer tower to a matching port on the back of your monitor. Once both ends are plugged in and the monitor is powered on, your screen should display your desktop. If it does not, the most common reason is that you plugged the cable into the wrong port on your tower — computers often have multiple video ports, and only one of them is active.
Before you start, locate the video ports on both your PC and monitor. These are small rectangular or circular openings, usually grouped together on the back of each device. Your monitor came with a cable, but if you cannot find it or it is damaged, you can purchase a replacement at any electronics store for $10 to $30.
Key Takeaways
- Most modern monitors use HDMI or DisplayPort cables, which are the same connectors used for TVs and other displays.
- Your PC tower likely has multiple video ports, but only one is connected to your graphics card — using the wrong port will result in a black screen.
- Power on the monitor before or after connecting the cable; the order does not matter, but the monitor must be switched on to display anything.
- If you see a black screen after connecting, try unplugging the cable and plugging it into a different video port on the back of your tower.
Identifying Your Video Ports
Your PC has several ports on the back, but only a few are for video. The most common ones are HDMI (a flat rectangular port), DisplayPort (similar to HDMI but with a notched corner), and DVI (a larger rectangular port with small holes). Older computers may have VGA ports, which are blue and have three rows of small holes. Your monitor will have one or more of these same ports on its back panel.
If your PC has a dedicated graphics card (a separate piece of hardware inside the tower), the video ports you should use are the ones on that card, not the ones built into the motherboard. These are usually lower on the back of the tower, below the motherboard ports. Using a motherboard port when a graphics card is installed will give you a black screen because the motherboard is not processing the video signal.
Check your monitor's manual or look at the ports themselves to see which type of cable it accepts. Most monitors sold in the last ten years use HDMI or DisplayPort. If your monitor has multiple video ports, any of them will work — you only need to use one.
Connecting the Cable Step by Step
Turn off your PC and monitor before plugging in the cable. This is not strictly necessary for modern equipment, but it reduces the small risk of a power surge damaging either device.
Locate the video cable that came with your monitor. One end will match the port on the monitor, and the other end will match a port on your PC. Plug the monitor end into the port on the back of the monitor first — push it straight in until you hear or feel a click. Some cables have small screws on the sides; tighten these by hand if your cable has them, as they keep the connection stable.
Plug the other end of the cable into a video port on the back of your PC tower. If your tower has multiple video ports, start with the lowest ones, as these are usually connected to a graphics card. Push the cable in firmly until it clicks or seats fully. Do not force it — if it does not slide in smoothly, you may be trying to insert it into the wrong type of port.
Plug the monitor's power cable into a wall outlet or power strip, then turn the monitor on using the power button on its front or side. Turn on your PC. Your monitor should display the boot screen or your desktop within 10 to 30 seconds. If the screen remains black, move to the troubleshooting section below.
What to Do If Your Screen Stays Black
A black screen after connecting usually means the cable is plugged into the wrong video port. Turn off your PC, unplug the video cable from the tower, and try a different video port. If your tower has three or four video ports, test each one. Plug the cable in, turn the PC back on, and wait 15 seconds before deciding whether that port works.
If you have a dedicated graphics card, make sure you are using one of the ports on the card itself, not the motherboard. Graphics card ports are typically positioned lower and further to the right on the back panel. If you are unsure which ports belong to the card, look for a separate metal bracket with multiple ports clustered together — that is your graphics card.
Another common cause is a loose connection. Turn off the PC, remove the cable from both ends, and reinsert it firmly into both the monitor and the tower. Make sure the cable is fully seated and any locking screws are hand-tight.
If you have tested all the video ports and the screen is still black, the cable itself may be damaged. Try borrowing a cable from another monitor or computer to rule this out. If a different cable works, you need a replacement cable matching your port type.
Understanding Different Cable Types
HDMI is the most common cable for modern monitors and PCs. It is flat and rectangular, about the size of a USB port but wider. HDMI carries both video and audio, so you may not need a separate audio cable if your monitor has speakers.
DisplayPort looks similar to HDMI but has a notched corner on one side. It is common on newer monitors and graphics cards and carries video and audio the same way HDMI does. DisplayPort and HDMI are not compatible with each other — you cannot plug an HDMI cable into a DisplayPort socket.
DVI is an older standard still found on some monitors and graphics cards. It is larger than HDMI and has small holes arranged in a grid pattern. DVI carries video only, so you will need a separate audio cable if your monitor has speakers.
VGA is the oldest standard and is now rare on new equipment. It is blue and has three rows of small holes. VGA carries video only and is gradually being phased out.
If your monitor and PC have different port types, you can use an adapter cable to bridge them. For example, an HDMI-to-DisplayPort adapter lets you connect an HDMI cable to a DisplayPort port. Adapters cost $10 to $25 and are sold at electronics stores and online.
Adjusting Your Display Settings After Connection
Once your monitor displays an image, you may need to adjust the resolution and refresh rate to match your monitor's capabilities. Right-click on your desktop and select "Display settings" (Windows) or go to System Preferences > Displays (Mac). Your PC should automatically detect your monitor and set a reasonable resolution, but you can change it if the text looks too small or too large.
If you are using two monitors, Windows will detect both and let you arrange them so your cursor moves naturally from one screen to the other. In Display Settings, you can drag the monitor icons to match their physical position on your desk.
Some monitors have brightness and contrast controls on the front or side panel. Adjust these to your preference after the connection is complete. If your monitor has a menu button, you can also access color and other settings through its on-screen menu.
Frequently Asked Questions
Can I use any cable that fits, or does the type matter?
The cable type must match your ports. HDMI only fits HDMI ports, DisplayPort only fits DisplayPort ports, and so on. Using an adapter lets you connect different types, but the cable itself must match one end or the other. If you are unsure which type you need, check your monitor's manual or look at the port shape on both devices.
Do I need to turn off my PC before plugging in the monitor cable?
No, but it is safer to do so. Modern equipment is designed to handle hot-plugging (connecting cables while powered on), but turning everything off first eliminates any small risk of damage from power surges. If your PC is already on, you can plug in the monitor cable without harm.
My monitor has multiple video ports. Does it matter which one I use?
No. If your monitor has two or three video ports, any of them will work. You only need to use one. Some people connect multiple cables for redundancy, but you only need a single cable for the monitor to display an image.
What if my PC has no video ports on the back?
Your PC may have a graphics card that requires a separate power cable. Check inside the tower to see if a graphics card is installed and whether it has its own power connectors. If the card is not powered, it will not work. Alternatively, your PC may be a laptop or all-in-one computer, which connects differently — those devices have built-in displays or use USB-C or Thunderbolt ports instead of traditional video ports.
Can I connect my PC to a TV instead of a monitor?
Yes. TVs use the same HDMI and DisplayPort cables as monitors. Plug the cable into the HDMI or DisplayPort port on your TV, then into your PC the same way you would with a monitor. Your PC will detect the TV and display your desktop on it. You may need to adjust the resolution in Display Settings if the text appears too small or too large on the TV screen.