First rule out the software
Before jumping to the conclusion that it is the hardware, a few settings need to be checked. These steps are free of charge and directly resolve part of the problem.
- Keyboard layout: Check the input source under System Settings → Keyboard. If the wrong layout is selected the keys produce different characters; the keyboard appears “faulty” but is completely sound.
- Slow Keys and Sticky Keys: When these options in the accessibility settings are switched on by mistake, they cause the keys to respond late or not to register at all.
- Mouse Keys: When this feature is switched on in Accessibility, part of the keyboard is assigned to cursor control and those keys do not type.
- Key repeat rate: It is located in the same settings section; in cases of double typing, this should be checked first.
External keyboard test
This is the most definitive method of isolating the problem. Connect a USB or wireless keyboard and test the affected keys. If everything is normal on the external keyboard, the software side has been ruled out and the problem is concentrated in the internal keyboard.
Problems caused by dirt and dust
In MacBook keyboards the key mechanism works within a very narrow gap. Micro particles that enter this gap cause the key not to press fully or to produce two characters with a single press. This problem is widely known especially on models with a thin mechanism.
Safe cleaning method
The approach recommended by Apple is cleaning with compressed air, and it is carried out as follows: hold the device tilted at an angle of about 75 degrees, blow across the keyboard sweeping from left to right, then tilt the device to the right and repeat the same procedure, and afterwards tilt it to the left and do it once more. Blowing from different angles increases the likelihood that the particle beneath the mechanism will come out.
Points to observe: do not attempt to remove the keycaps — the mechanism is fragile and repairing a broken clip is far more difficult than seating the keycap back in place. Do not use liquids or cleaning chemicals. Do not interfere with the mechanism using metal or sharp objects.
Liquid contact: a race against time
When liquid is spilt on the keyboard, the order in which you act determines the outcome directly:
- Switch it off immediately. Do not wait for the system to shut down properly; switch it off by holding the power button.
- Disconnect the charging cable and disconnect any accessories that are connected.
- Turn it upside down. Turn the device upside down while it is open (tent position) and allow the liquid to drain out from inside.
- Do not try to switch it on. Checking "whether it still works" causes a short circuit on wet circuitry.
- Do not apply heat. A hairdryer pushes the liquid between the components and increases the damage through heat.
The critical point is this: even if the device appears to work normally after drying out, the liquid will have started corrosion on the logic board. This process advances over days and weeks; a problem that begins in the keyboard can turn into a logic board fault over time. For this reason, getting the device to a service centre for cleaning and assessment as soon as possible after liquid contact prevents a far more expensive repair later on.
The probable cause according to the symptom
A single key does not respond
Usually dirt beneath the mechanism. Cleaning is the first step to try.
A key types twice
A problem with the mechanism or the key repeat setting. Check the setting first.
An entire row does not work
Ribbon cable contact or a fault in the keyboard circuit. This is a matter for the service centre.
The keyboard is completely dead
The connection cable or the mainboard side. Confirm this with an external keyboard test.
If the keyboard is completely unresponsive
If no key works at all, first restart the device; temporary software hang-ups can be resolved this way. Then check for macOS updates. If these steps produce no result and an external keyboard works without problems, the ribbon cable connecting the internal keyboard to the logic board, or the keyboard circuit itself, is the likely cause. This requires opening the device.
If the trackpad does not work either, alongside the keyboard, the cause usually lies at a shared connection point, or a swollen battery is pressing against these components. If there are signs of swelling (bulging of the bottom cover, the device not sitting flat), stop using the device; details in our charging guide.
Repair options
MacBook keyboards are manufactured integrated into the top case; for this reason, replacing a single key is not possible on most models. When replacement is required, the procedure means renewing the whole assembly in which the keyboard sits, and it is handled together with the battery.
That is why it is important to keep to the order: software settings first, then cleaning, and the hardware decision last. A proportion of the devices that come to us with this complaint are resolved in the first two steps, and no replacement is needed.
At our service centre in Çankaya, we first carry out isolation tests on keyboard complaints and resolve cases that can be fixed by cleaning without proposing a replacement. Where a replacement is required, we set out clearly before the work begins what its scope is and what will be renewed.
MacBook Repair
Keyboard diagnosis and repair
Screen Replacement
Display panel and top case work
Data Recovery
Data safety after liquid contact