Yes, you can connect a mouse to the USB ports on your LG 34GP83A-B, but with an important limitation

The LG 34GP83A-B has four USB 3.0 ports built into the back of the monitor. You can plug a mouse directly into one of these ports, and it will work — the monitor acts as a USB hub, passing the connection through to your computer. However, this only works if your computer is also connected to the monitor via the USB upstream port (the single port labeled differently from the others). Without that upstream connection, the mouse ports are inactive.

The upstream port is the cable that ties the monitor's USB hub back to your computer. Think of it like the main water line to a house — the four regular USB ports are the faucets, but they need that main line connected or nothing flows. If you connect your computer to the monitor using only HDMI or DisplayPort for video, the USB ports on the monitor will not recognize any devices you plug into them.

Key Takeaways

  • The four USB 3.0 ports on the back of the LG 34GP83A-B work only when you connect the monitor's upstream USB port to your computer with a cable.
  • If you connect your computer to the monitor using only video cables (HDMI or DisplayPort), the USB ports will not function.
  • Once the upstream port is connected, you can plug a mouse, keyboard, or other USB device into any of the four ports and use it normally.
  • The upstream port is usually a USB-B or USB-C port on the monitor; check your monitor's manual to identify which port it is.

How to set up the USB ports on your monitor

First, locate the upstream port on the back of your LG 34GP83A-B. This is the single port that looks different from the other four — it may be labeled "upstream" or "USB in" in your monitor's manual. Connect a USB cable from this port to an available USB port on your computer (usually on the back of your desktop tower or the side of your laptop).

Once that cable is in place, the four regular USB 3.0 ports become active. You can now plug your mouse into any of them. The monitor will pass the signal to your computer, and your operating system will recognize the mouse just as if you had plugged it directly into the computer. You can also use these ports for keyboards, external hard drives, or other USB devices.

What happens if you only connect video cables

Many people connect their monitor using only HDMI or DisplayPort — these cables carry the picture from your computer to the monitor, but they do not set up the USB hub. If you plug a mouse into the monitor's USB ports without connecting the upstream cable, nothing will happen. The mouse will not light up, and your computer will not detect it.

This is a common source of confusion because the ports are physically there and look like they should work. The monitor itself is not broken; the USB hub straightforward has no connection back to your computer. Adding the upstream cable solves the problem when ready.

USB 3.0 speed and what devices work best

The four USB ports on the LG 34GP83A-B are USB 3.0 standard, which means they transfer data at up to 5 gigabits per second. This is fast enough for any mouse or keyboard, and also works well for external hard drives, USB flash drives, and other common peripherals. You will not notice any lag or delay with a mouse, even a wireless receiver that uses USB.

If you have older USB 2.0 devices, they will still work in these ports — USB is backward compatible. The device will straightforward run at its own slower speed rather than the full 3.0 speed. For a mouse, this makes no practical difference.

Wireless mice and the USB receiver

If you use a wireless mouse, you need to plug the small USB receiver (the dongle) into one of the monitor's USB ports, not the mouse itself. The receiver is what communicates with your computer. Plug the receiver into any of the four USB 3.0 ports on the monitor, and your wireless mouse will work normally once the upstream cable is connected.

Some wireless mice use Bluetooth instead of a USB receiver. Bluetooth mice do not need a USB port at all — they connect directly to your computer's Bluetooth radio. You can use a Bluetooth mouse with the LG 34GP83A-B without plugging anything into the monitor's USB ports.

Troubleshooting when the mouse does not work

If you plug a mouse into the monitor and it does not work, the first thing to check is the upstream cable. Unplug it and plug it back in firmly — a loose connection is the most common cause. Make sure both ends are fully seated: one end in the monitor's upstream port and the other in a USB port on your computer.

If the upstream cable is connected and the mouse still does not work, try plugging the mouse directly into your computer instead of the monitor. If it works when plugged directly into the computer, the problem is with the monitor's USB hub. If it does not work even when plugged directly into the computer, the mouse itself may be faulty or need new batteries (if wireless).

Frequently Asked Questions

Do I need to connect the upstream cable if I only want to use the monitor for video?

No. If you only care about the picture on the monitor and do not plan to use the USB ports, you do not need the upstream cable. You can connect the monitor to your computer using only HDMI or DisplayPort. The USB ports will straightforward remain inactive.

Can I use a USB hub instead of plugging devices into the monitor?

Yes. If you do not want to use the monitor's built-in USB ports, you can plug a separate USB hub into your computer and use that instead. The monitor's USB hub is convenient because it is already there, but it is not required.

What if my computer does not have an available USB port for the upstream cable?

You can use a USB hub plugged into your computer to create more ports, then connect the monitor's upstream cable to one of those hub ports. The monitor's USB hub will work through the external hub without any problems.

Will the monitor's USB ports work if I connect it to a laptop?

Yes, the same rules explore. Connect the upstream cable from the monitor to any available USB port on your laptop, and the four USB ports on the monitor will become active. This works with any computer that has a USB port.

Can I charge my phone through the monitor's USB ports?

Yes, if your phone charges via USB. Plug the charging cable into one of the four USB 3.0 ports on the monitor (with the upstream cable connected), and your phone will charge. The speed will be the same as charging from your computer directly.