When trying to fix a faulty gadget, you’ve probably read or heard the following: Unplug it, wait 10 seconds, then plug it back in. Often, that’s all it takes to fix the problem. What does it do and why does it work?
You perform a forced restart
Unplugging something usually works because many consumer devices, like cable modems, routers, and streaming TV boxes, have small computers inside. Disconnect and reconnect them force these computers to restart and clear any temporary software glitches.
The internal computers of these devices are working integrated software (called firmware) which controls the behavior of the device. Sometimes the firmware contains bugs that can lead to error states, memory leaks, or crashes. Restarting the device forces the internal computer to restart, which clears the device’s memory and forces it to reload and rerun the software from scratch.
This is a temporary solution
Rebooting a device by unplugging it can sometimes work well, but it’s actually only a temporary solution. It does not fix the underlying issue that caused the malfunction, hang up, or crash in the first place. To do this you will need to download and perform a firmware update for that particular device.
Hardware failures of a device can also cause problems that restarting can temporarily resolve. However, a permanent fix will require repair or replacement of the device. In these cases, it is best to consult the manufacturer’s support service.
Devices that often benefit from the Unplug / Reconnect method
As a general rule, it is best to unplug only devices designed as consumer devices that do not have an on / off switch. These devices load their software from firmware, which usually will not be corrupted by abrupt power cycling.
Some examples are:
Streaming and Cable TV Boxes
Smart home appliances
What if a device has a power switch?
If the device you are troubleshooting has a power switch, try using it to restart the device first, as this could potentially fix the issue.
Sometimes, however, change is not enough. Nowadays, many gadgets use “soft” power switches that rely on software control. Some of these switches only put a device into “sleep” mode, while others can initiate an internal shutdown sequence.
Disabling a “soft” power button and turning it back on on a faulty device will not necessarily force an internal restart of the computer. So, you may still have to take the next step: unplug the device and plug it back in.
When you shouldn’t unplug a faulty device
It is generally a bad idea to suddenly turn off the power to devices such as desktops or laptops. This is because they load their software from a rewritable source, such as a hard drive or SSD. They also often use these devices to store temporary settings while the computer is running.
If you suddenly turn off the power to your computer, it may interrupt a writing process and corrupt the file system on your machine.
Sometimes, however, a computer becomes unresponsive at all and there is no way to fix it in the software. In these cases, you can pull on the power cord and then restart the machine as a last resort. There may be data loss, but sometimes you just have no other choice.
There are also certain types of sensitive scientific and medical equipment that should never be suddenly unplugged. It could cause damage or put someone’s life in danger.
Obviously, you want to make sure that any device you’re about to unplug won’t endanger anyone’s safety when it disconnects and turns back on.