Laptop casing parts: covers, bezels and hinges explained

The A, B, C and D covers

Manufacturers and repairers name the four main shells of a laptop by letter, and part descriptions often use the letter alone, as in A-cover or D-cover.

• The A cover, also called the back cover, display back cover, LCD cover or lid, is the outside of the screen, usually with the logo on it.
• The B cover is the bezel, the frame around the screen on the inside of the lid.
• The C cover is the palm rest, top case or (in HP part names) top cover, the surface around the keyboard and touchpad. On many laptops it comes with the keyboard already fitted.
• The D cover is the bottom base, or bottom case, the underside with the rubber feet and vents.
• Smaller casing parts include the hinges, hinge covers, rubber feet and the doors that cover the memory or drive bays on older models.

Signs a casing part needs replacing

• The lid will not stay open, flops back, or creaks and flexes when opened. This is usually a broken hinge or a broken hinge mount.
• The screw posts that hold the hinges have broken out of the back cover or the base. A new hinge will not hold until the cover or base is replaced too.
• The case is cracked, or a gap has opened between the covers along the edge.
• The bezel lifts away from the screen, or clips around the edges have snapped.
• Rubber feet are missing, so the laptop rocks or the vents underneath are blocked.

Bezels

Some laptops, especially touch-screen models, have no separate bezel: the glass covers the front of the lid and the screen is sold as one assembly. On others the bezel is held on with adhesive rather than clips.

Why the exact version matters

Covers that look alike can differ in small ways that stop them fitting. One laptop model is often built in several versions, and each can need a different cover:

• Touch and non-touch screens often use different back covers and bezels.
• Different screen panels in one model, such as touch, privacy or OLED, can need a different lid.
• The camera can differ between versions, for example a standard camera, an infrared camera for face sign-in, or a privacy shutter, and the bezel or back cover has to match it.
• A fingerprint reader, smart card reader, backlit keyboard or mobile broadband antenna can change the palm rest or the back cover.
• Colour and finish can vary between versions.
• Some palm rests come with the keyboard, touchpad, speakers or even the battery fitted, and some come bare. The part description says which.

How to choose the right part

Use these checks in order:

• Look inside the old part for a printed label or part number.
• HP labels usually show a spare part number in a form like 123456-001, L12345-001 or M12345-001. Lenovo uses a FRU number. Dell prints a short part number, often after the letters DP/N.
• The number moulded into the plastic is often the factory's own number rather than the maker's spare number. Send it anyway, because it helps identify the part.
• If the part is not to hand, use the laptop's exact model or product number from the label underneath, and its serial number. The serial number identifies which version of the model you have.
• Check the cut-outs for ports, the camera and any readers against the old part, and the colour.

Hinges

Hinges are sold as a left and right pair or one side at a time, and touch-screen versions often use different, stiffer hinges. On many laptops the hinges come fitted to the back cover or the base and are not sold separately. Before ordering hinges alone, check the screw mounts in the back cover and the base. When the hinge has torn its mount out of the plastic, the cover or the base needs replacing as well, or the new hinge will break loose again.

Fitting casing parts safely

• Shut the laptop down fully and unplug it. Remove the battery if it is removable. If it is internal, disconnect it as soon as the bottom cover is off, before touching anything else.
• Use plastic opening tools rather than metal ones, to avoid scratching the case or cutting a cable.
• Lift a bezel from its outer edge, never from the screen side, so the glass does not crack.
• Keep the screws in order. They are often different lengths, and a long screw in the wrong hole can push through the keyboard or the screen.
• Move every part that is not supplied with the new cover across from the old one, such as the touchpad, speakers, antennas or the rubber feet.