Software tower · floor

Why is my bluetooth not working, or just switched off

Why is my bluetooth not working covers three different situations that look identical: the switch will not turn on, the switch is greyed out, or the switch has disappeared from settings altogether. In the manufacturers’ documentation, the first two are usually a state rather than a fault — and the states are published.

Start with the setting that switches Bluetooth off without anyone noticing, because it does three different things depending on what you are holding.

Read those three together and the odd one out is clear. On an iPhone, Airplane Mode is not a reason for Bluetooth to be off: Apple keeps it on by design and says so. On Windows it is off. On Android it is off the first time and then follows whatever you chose last — so the same switch, on the same flight, can leave you with Bluetooth on or off depending on a decision you made months ago.

Apple adds one more rule in the same place, and it is the one that surprises people: “If you turn off Bluetooth while you’re in Airplane Mode, your device turns off Bluetooth the next time that you turn on Airplane Mode.” The exception has a memory too.

Then the case that generates the most unnecessary alarm.

Now the third situation, which is the one that is sometimes a real fault.

It is worth pausing on that last sentence rather than skipping past it. A missing Bluetooth switch on a desktop is not always a problem to be solved; on machines without the hardware it is the correct display. Microsoft says it in four words, and it saves an evening of driver hunting.

The remaining family of cases has nothing to do with the switch at all.

So the order that comes out of the documentation. Check Airplane Mode first, knowing that what it did depends on your platform and, on Android, on a choice you have forgotten making. On an iPhone, check Settings rather than Control Centre, because the dimmed icon there means disconnected. On Windows, if the switch is absent, read Microsoft’s own list of causes and check first whether the machine has Bluetooth at all. And if the switch is on and a device still will not appear, look at where that device is connected now and at the discovery setting that filters the list.

A note on scope. This floor is about Bluetooth itself refusing to work. Pairing a new accessory is a different job with its own documented gaps, and a car that connects but stays silent is a third thing again; both are linked below.

What this page will not do is tell you your Bluetooth chip has failed. Microsoft lists hardware malfunction among five possible causes and puts it fourth, after settings, drivers and services.

It will not recommend a USB Bluetooth adapter. It is a real answer for a machine without the hardware, none has been tested here, and Microsoft notes that USB devices too close together cause their own interference.

And it will not tell you to reinstall the driver first. There is a service to restart and a power setting to untick before that, both published, and both reversible in seconds.

What this tower will not do

It will not tell you the Bluetooth hardware has failed. Microsoft lists that fourth of five causes, after settings, drivers and services.

It will not recommend a USB Bluetooth adapter, although for a machine without the hardware that is the real answer. Nothing here has been tested.

It will not tell you to reinstall the driver first. A service restart and a power setting come before it, and both take seconds to undo.

And it carries no affiliate links, including for adapters and headphones, which is what a page ranking for this question would exist to sell. What holds instead is simple: the three airplane-mode behaviours, the meaning of the dimmed icon and the five causes above are quoted from Microsoft, Apple and Google directly, each from the page that publishes it.