Why Your USB Sharing Switch Drops Devices and How to Fix It

Quick answer

A USB sharing switch that drops devices is almost always fighting a power or cabling limit, not failing internally. Start by moving the switch to a powered hub instead of a single device, then check cable length and the order you press the button. If the switch still drops a device that works when plugged in directly, the switch is the problem and should be replaced.

Symptom: the device disconnects only when you switch computers

If the device works fine on either computer when connected directly but drops every time you press the switch, the switch is re-enumerating the USB device and the host is not re-detecting it cleanly. This is common with printers and scanners that hold a driver session open. Close the printer or scanner software on the computer you are leaving before you press the button, then switch. If the device still drops, the issue is the switch's handoff, not the device.

Symptom: the device drops during use, not at the switch press

A drop mid-task points to power or bandwidth. USB 2.0 supplies limited current per port, and a bus-powered device plus a long cable can push past what the host delivers. Move the device to a powered hub connected to the switch, or connect the switch to a powered hub on each computer. Keep cable runs short; a passive extension on top of the switch cable is a common cause of intermittent drops.

Symptom: one computer sees the device, the other does not

Check that both computers have the device driver installed before you switch. A computer that has never seen the printer or scanner will not load it just because the switch connects it. Plug the device directly into the second computer once to install the driver, then return it to the switch. Also confirm both computers are awake; a sleeping host can drop the switch connection and not recover it until you press the button again.

When to stop adjusting and replace the switch

If the device works directly on both computers, the cables are short and known-good, and the switch still drops it, stop troubleshooting. A USB 2.0 sharing switch is a simple pass-through device with no firmware settings to tune. Repeated drops after these steps mean the switch itself is the limit. Replace it rather than adding more hubs and adapters, which only add more points of failure.

Set up the switch so drops are less likely from the start

Connect a powered USB hub to the switch instead of a single device. That lets you switch everything on the hub with one button and gives each device its own power budget. Label which computer is A and B so you press the right direction, and leave the switch in one position when you shut down rather than switching mid-shutdown. These habits remove most of the everyday causes of a usb switch drops connection problem.

Diagnosis: match the symptom to the cause

• Drops only when you press the button: The switch is re-enumerating the device and the host is not re-detecting it. Close the device software on the computer you are leaving, then switch. If it still drops, the switch handoff is the limit.
• Drops during use, not at the switch press: Power or bandwidth is the usual cause. Move the device to a powered hub connected to the switch and shorten cable runs. If drops continue with short cables and a powered hub, replace the switch.
• One computer never sees the device: The driver is missing on that computer. Plug the device directly into it once to install the driver, then return it to the switch. No driver, no device, no matter how the switch is set.
• Device works directly but not through the switch: Test the same device and cable directly on both computers. If both work directly, the switch is the failing part. Stop adding adapters and replace the switch.

Product facts

• Plugable USB 2.0 Sharing Switch: The Plugable USB 2.0 Sharing Switch (USB2-SWITCH2) shares one USB device between two computers with the press of a button, and you can attach a powered USB hub to the switch instead of a single device. The powered-hub option is the main fix for power-related drops: it gives every device on the hub its own power instead of drawing from the switch alone.
• Plugable USB-C Gigabit Ethernet Adapter: The Plugable USB-C Gigabit Ethernet Adapter (USBC-E1000) adds wired gigabit networking over USB-C and is USB bus-powered. If you are sharing a network adapter through the switch, a bus-powered adapter is more sensitive to the power limits described above, so keep its cable short and avoid stacking it behind an unpowered hub.