What Was Happening
A customer from Wandsworth SW18 brought in a MacBook Pro 13-inch 2019 (A2159) following a coffee spill across the keyboard. They had reacted quickly — turning the machine off immediately and draining it upside down — but by the time they brought it in, several rows of keys were unresponsive and others had become sticky. The trackpad was working, the machine was powering on, and the screen was functioning normally.
The customer needed the machine for work and wanted to understand whether the keyboard could be repaired or whether a full replacement was required.
Our Diagnosis
The A2159 uses Apple’s third-generation butterfly keyboard mechanism — a design that is extremely thin and offers very little clearance between keycap and internal mechanism. When liquid enters, it has nowhere to go except directly onto the key switch contacts and along the ribbon connector channel toward the logic board.
We opened the machine and inspected both the keyboard assembly and the logic board. The keyboard assembly showed visible contamination at multiple points — residue from the coffee was visible under several key clusters. The ribbon connector between the keyboard and logic board also showed traces of liquid ingress.
The logic board itself was clear. The customer’s quick response had prevented liquid from spreading further into the machine.
On this generation of MacBook Pro, the butterfly keyboard cannot be individually serviced at the key level — the switch mechanisms are sealed and the keyboard is designed as a single replaceable assembly. Attempting to clean individual switches on a contaminated butterfly keyboard is not reliable; the geometry of the mechanism means residue lodges in places that isopropyl alcohol cannot reach without full disassembly of the key mechanism itself.
How We Fixed It
We replaced the full keyboard assembly with a compatible replacement. Before fitting the new keyboard, we cleaned the logic board connector area and the surrounding surface thoroughly with isopropyl alcohol to ensure no residue remained that could cause future issues.
The new keyboard assembly was fitted and all ribbon connectors were reseated carefully. We then tested every key across the full keyboard matrix, confirmed all modifier keys and function keys, and tested the Touch Bar (present on this model) to confirm it was responding correctly.
The Result
The MacBook Pro was returned to the Wandsworth customer the same day with full keyboard function restored. All keys responded correctly, the Touch Bar was working, and the logic board showed no secondary effects from the spill.
Why Coffee Spills Are More Damaging Than Water
Plain water causes short-circuit risk and some mineral residue, but it is relatively straightforward to clean and does not corrode aggressively. Coffee — particularly with milk and sugar — introduces acids and sugars that remain chemically active on board surfaces and key contacts even after the water evaporates. Sugary residue is hygroscopic, meaning it continues to absorb moisture from the air, which keeps the corrosion process active indefinitely if not professionally cleaned. A MacBook that has had a coffee spill and “dried out” naturally will often develop progressive faults over the weeks and months following the spill, even if it appears to work immediately after.
Prevention Tips
- Keep drinks away from the keyboard area — the butterfly mechanism has essentially zero tolerance for liquid ingress compared to older scissor-switch designs
- If a spill occurs, power off immediately using the power button, do not attempt to restart to check whether the machine still works
- Turn upside down and drain, then bring to a professional as soon as possible — do not attempt to dry with a hairdryer or leave in an airing cupboard
- For machines you use near food and drink regularly, a keyboard cover film provides meaningful protection against incidental splashes
Local Help in Wandsworth SW18
We carry out MacBook keyboard and liquid damage repairs at our Putney workshop for customers across Wandsworth SW18. Free collection is available from SW18 so you don’t need to carry a liquid-damaged machine on public transport.
Related Services
- MacBook Repair — hardware and keyboard repairs for all MacBook models
- MacBook Repair in Wandsworth — local service for SW18
- Liquid Damage Repair — cleaning and board repair for liquid-affected devices
More Case Studies
- MacBook Air water damage repair in Wandsworth — liquid damage where board cleaning alone restored the machine
- MacBook Pro battery swelling repair in Putney — another common MacBook fault requiring assembly-level work
- MacBook Pro A1708 motherboard and trackpad data recovery — more complex repair on a nearby generation