The Guide to Refurbished Machines: How to Judge Quality from the Screw Marks

Want to avoid buying a refurbished phone? The key is to learn how to inspect the screw holes. We'll teach you how to quickly determine if a phone, computer, or other electronic device has been disassembled by checking the screw types, location of scratches, and degree of oxidation.With these practical tips, you can avoid the pitfalls.

Why can screws expose the secrets of a device?

When we buy a second-hand cell phone or computer, the one thing we fear most is that we'll get a refurbished machine.But if you look closely at the small details, such as the screws, you can discover a lot of problems.When assembling equipment, regular factories use specially designed screwdrivers, and have strict measures in place to prevent scratches on the assembly line.

Three steps to screw problems.

Observe whether the screws are in the same position.

First, he goes around the machine and checks to see that all the screws are the same depth.When the factory assembles the parts, it uses a machine to screw in the screws, so the depth of insertion is almost exactly the same for each one.If you find that a screw is noticeably sunken in or protruding, it may well have been replaced.

Checking the surface of screws for scratches.

The screws are examined by shining a flashlight on them at an angle to see if there are any cross-hatching or burrs.The screwdriver heads used by legitimate manufacturers are very precise and will not leave any scratches on the screws.If the edge of the screw slot is worn and shiny, there is an 80 % chance that the phone has been opened up.

Pay attention to the type of screw.

Today, many brands use their own proprietary screws, such as Apple's pentagon-shaped screws or Microsoft's triangular tamper-resistant screws.If the special screws have been replaced with ordinary crosshead screws, or if the screws have different colors, then the device has certainly been tampered with.

These are things to watch out for.

If there are any paint chips or glue marks around the screws, don't believe the seller when he says that it's just a flaw from the factory.Some refurbishers use paint pens to cover up the marks. If the screws feel rough or are a different color than the surrounding metal, you can be sure the machine has been refurbished.

A few tips on how to do the tests.

It's recommended that you carry a 10x loupe with you, as the lighting in secondhand markets is often poor.You can also use a cotton swab dipped in alcohol to wipe the screws. If you see black marks, that means the screws may have been replaced. The screws from the original manufacturer have an anti-oxidation coating, which makes it hard for them to rust.Remember to ask the seller to confirm that the warranty stickers are intact, and to check the screws.