Why does my external hard drive keep disconnecting?

The usual culprits are a loose or worn cable, a USB port not supplying enough power, or the system putting the drive to sleep. Less often it is the drive itself failing. Start by swapping the cable and port, and disabling USB power saving, which fixes most cases.

How do I stop my external drive from disconnecting?

Try a different cable and a different port, ideally one directly on the computer rather than a hub. Turn off USB selective suspend or power saving so the system stops sending the drive to sleep. If it persists across machines, check the drive's health.

Is a disconnecting drive a sign it is failing?

Sometimes, but usually it is power or cable related. Rule those out first. If the drive still drops out on different cables, ports and computers, and its SMART data looks bad, then it may be failing and worth replacing.

Why Does My External Drive Keep Disconnecting?

Published: 17 août 2026

Live answer · Amazon.com

Pulling live prices…

Live data across PricePerGig listings. Prices may change; Updated every few hours.

📊 Au 29 août 2026, le HDD typique sur Amazon.fr est à 197 €/TB ou 0,197 €/GB sur les 1,645 offres en direct que nous suivons, avec le plus grand choix de disques autour de 101 €/TB ou 0,101 €/GB. Les meilleures offres sur Amazon.fr démarrent autour de 312 € pour 8TB (39 €/TB), 525 € pour 14TB (37,5 €/TB) et 650 € pour 20TB (32,5 €/TB). Le meilleur rapport qualité-prix actuel est 16TB à environ 27,5 € le TB.

Sourced from real discussions on r/techsupport and r/DataHoarder, cross-checked against live PricePerGig listings.

External drive vanishing mid-copy, then reappearing, then dropping again? Maddening. Let me help you track down why, because it is usually a simple fix.

Most of the time it is not the drive failing. It is power, a cable, or a sleep setting.

Work through these in order and you will almost certainly solve it.

The table above shows the live price per TB on your marketplace, just in case the drive really is on its way out.

First suspect: the cable and port

This is the most common cause, and the easiest to test.

USB cables wear out, work loose, or were never great to begin with. Ports vary in quality and power too.

So try this first.

Swap the USB cable for a different, good quality one.
Plug into a different port, ideally one directly on the computer rather than a hub.
If you use a USB hub, try without it. Hubs often cannot supply steady power to a drive.

A huge share of disconnecting drives are cured right here. Cheap fix, big win.

Second suspect: power saving

If cables and ports do not fix it, look at sleep settings.

Computers love to save power by putting USB devices to sleep. The trouble is, a drive that gets sent to sleep mid-task can drop the connection and look like it disconnected.

The fix is to turn off USB power saving, sometimes called selective suspend, so the system stops nodding the drive off. On a laptop, also check that the drive is not losing power when the lid setting kicks in.

This solves a lot of the cases that survive the cable swap.

Third suspect: not enough power

Bigger drives, especially desktop ones, are hungry.

A drive drawing more power than the port can supply will brown out and drop off, particularly through a hub or a weak laptop port.

Use a port directly on the computer.
If the drive has its own power adapter, make sure it is plugged in and working.
Avoid daisy chaining through unpowered hubs.

Give the drive clean, steady power and the random drops often stop.

When it might actually be the drive

If you have tried different cables, ports, and power settings, on more than one computer, and it still drops out, then look harder at the drive.

Check its SMART health. If the numbers look bad, or it makes odd noises, the drive itself may be failing.

At that point, back up anything important right away and plan a replacement using the live prices above.

The bottom line

A constantly disconnecting external drive is usually a cable, port, or power saving problem, not a dying drive. Swap the cable, change the port, skip the hub, and turn off USB power saving.

If it still drops out everywhere after all that, check the drive’s health and replace it if needed. Grab a reliable replacement from the live prices above, and enjoy a drive that actually stays connectd.

First suspect: the cable and port

Second suspect: power saving

Third suspect: not enough power

When it might actually be the drive

The bottom line

Related questions