Buying Used: What to Check Before You Pay

Used computers are frequently the best value available, and the difference between a bargain and a mistake comes down to a handful of checks that take ten minutes.

Where the value actually is

Ex-business laptops. Built better than consumer machines, come off lease in large numbers, and a three-year-old model is more than adequate for ordinary work. The best value in the category by some margin.

Manufacturer-refurbished machines, which carry a warranty and have been tested.

Desktops, which are cheap used and easy to upgrade afterwards.

Where the value is not: consumer laptops sold privately after heavy use, anything with a failed battery presented as fine, and machines close to the end of their support period.

The four things that decide it

1. Is it still supported?

Check the model against the manufacturer's support timetable before anything else.

A machine that stops receiving updates in a year is a one-year machine, whatever the price. See when a device stops receiving updates.

This single check eliminates a large share of bad purchases.

2. Battery health, on anything portable

Both major systems report cycle count and health in system information. Look at it in front of the seller.

A battery at 60% health is a battery needing replacement, which is a real cost and sometimes an awkward one.

"It lasts all day" without the figure is not information.

3. Drive health

Check SMART data with a reporting tool. Reallocated sectors, pending sectors and power-on hours.

A drive with warnings is a drive to replace, which is cheap if it is the only issue and worth knowing before you pay.

Note whether it is solid state or mechanical, which determines how the machine will feel. See reading a specification sheet.

4. Whether it is actually the owner's to sell

Check activation lock and device management. Both Apple and Windows machines can be locked to an account or enrolled in an organisation's management, and a machine that is remains locked or managed after you buy it.

On a Mac, activation lock makes the machine unusable to anyone else.

On a business laptop, enrolment in corporate management can mean it phones home and is remotely wiped.

Ask the seller to sign out of everything and remove it from their account, in front of you. A seller who cannot or will not is telling you something.

The ten-minute inspection

Turn it on and let it reach the desktop. Note how long it takes.

Check the system information: model, processor, memory, storage type and capacity, system version.

Check battery and drive health, as above.

Type on every key. A dead key is expensive on a laptop.

Check the screen — a plain white and a plain black image show dead pixels, backlight bleed and marks.

Test the ports. Plug something into each.

Test the trackpad, camera, speakers and microphone.

Check Wi-Fi and Bluetooth connect.

Listen. Grinding or a rattling fan is a repair.

Look at the hinges and the case for cracks and previous repairs.

Run something demanding for a few minutes and see whether it gets uncomfortably hot or the fan becomes very loud.

Questions to ask

Why are you selling it?

How old is it, and do you have the receipt? Which also establishes whether warranty remains.

Has it been repaired?

Has it had liquid on it? Liquid damage returns months later through corrosion, and it is the failure most worth avoiding.

Is the battery original?

Are the charger and any adapters included? A proprietary charger is expensive to replace.

Where to buy

Manufacturer refurbished — highest price of the used options, with a warranty. Frequently the right choice for someone who does not want to inspect anything.

Business refurbishers — ex-lease machines, tested, usually with a short warranty. The sweet spot for value.

Marketplace and private sale — cheapest and highest risk. Inspect in person, pay through a protected method, and never by bank transfer to a stranger. See scams that target home users.

Auction sites — variable, and read the description for what is not included.

After you buy it

Wipe it and install fresh. Do not use a system installed by someone you do not know — you cannot know what is on it.

Check the drive health again after a few days of use.

Register it if a warranty transfers.

Budget for a battery on an older laptop, and possibly a drive.

Clean it properly, which frequently improves temperatures noticeably. See cleaning and maintaining.

What makes a cheap machine expensive

A failed battery on a model where replacement is awkward.

A drive that fails in month two, taking your files.

No support remaining, so it is unsafe for anything sensitive within a year.

Liquid damage that surfaces later.

A proprietary charger that costs a third of the machine.

All five are checkable before paying.

The short version

Ex-business laptops are the best value in the category.

Check the support timetable first — a machine losing updates next year is a one-year machine.

Check battery and drive health in front of the seller, with the actual figures.

Make them sign out and remove it from their account before you pay, or you may buy a locked machine.

And wipe it and install fresh afterwards, because you cannot know what is on a system installed by a stranger.

For independent consumer guidance on technology, scams and online services, see FTC Consumer Advice.