Written by Courtney Bentley with AI assistance, based on 17 years of hands-on experience
Not every MacBook that has been exposed to liquid shows obvious symptoms. In our Hyde Park workshop, we regularly see machines that were "working fine" for weeks or months after a minor spill — until a component finally corroded through and the MacBook stopped charging, lost display output, or simply refused to power on.
Since 2009, we have repaired over 25,000 Macs, and a significant percentage of those were cases where the owner did not even know liquid damage had occurred. This guide teaches you how to identify the signs — whether you are checking your own MacBook after a suspected spill, or inspecting a second-hand purchase before handing over your money.
The 10 Physical Signs of Water Damage
1. Sticky or Unresponsive Keys
Liquid that seeps under the keyboard leaves residue as it dries. You will notice keys that feel tacky, require extra force to press, or do not spring back cleanly. On butterfly keyboard MacBooks (2016–2019), even a small amount of liquid can cause multiple keys to stick because the low-profile mechanism traps residue against the dome switch. Present in approximately 60% of liquid damage cases we assess.
2. Trackpad Clicking Feels Different
The Force Touch trackpad uses haptic feedback to simulate a click. Liquid contamination affects the pressure sensors underneath, causing the click to feel mushy, inconsistent, or to register ghost clicks.
3. Port Oxidation and Discolouration
Examine the USB-C ports, headphone jack, and MagSafe connector with a torch. Look for green or white powdery deposits, darkening of metal contacts, and corrosion buildup around port edges. We see corroded USB-C ports in approximately 40% of liquid damage assessments.
4. Screen Fogging or Watermarks
Liquid that reaches the display assembly can cause visible fogging between the LCD panel and the glass cover. Display fogging typically requires a full display assembly replacement (R4,500–R8,500 depending on model).
5. Intermittent Charging Issues
If your MacBook charges intermittently, the USB-C charging IC or MagSafe connector may have corrosion. Check whether charging works consistently on one port but not the other — if only one port charges, the charging IC on the other side may be corroded.
6. Unexplained Battery Drain
Liquid damage to the battery connector or power management circuitry can cause abnormal battery behaviour: rapid drops, stuck percentages, or macOS reporting "Service Recommended" on a battery that was fine weeks ago.
7. Fan Running Constantly or Not at All
Corrosion on the fan connector or temperature sensor circuits causes fans that run at full speed constantly or fans that never spin. Both are dangerous.
8. Speaker Distortion or Crackling
Liquid reaching the speaker chambers causes crackling at medium-to-high volumes, imbalanced output, or complete silence. Speaker damage from liquid is usually permanent. Replacement cost: R1,200–R2,500 per speaker.
9. Bluetooth and Wi-Fi Intermittency
Corrosion on the antenna connector, Wi-Fi chip, or surrounding passives causes random Bluetooth disconnections, Wi-Fi drops, reduced range, and AirDrop failures. These symptoms are often wrongly attributed to software issues.
10. Mineral Deposits Visible Inside Ports
White, green, or crystalline deposits visible inside USB-C or headphone ports when using a torch are definitive evidence of liquid exposure — minerals do not form spontaneously inside ports.
Apple’s Liquid Contact Indicators (LCIs)
Apple places small chemical-reactive indicators inside every MacBook. These stickers are normally white or silver, but change to red or pink permanently when exposed to liquid. They cannot be reset or reversed.
LCI Locations by MacBook Model Era
MacBook Air and MacBook Pro (2013–2015, Retina): Multiple LCIs visible through the bottom case vents near the hinge area with a bright torch.
MacBook Pro (2016–2020, Touch Bar era): LCIs on the logic board near the battery connector, SSD area, and fan assembly. Typically 4–6 indicators. Only visible after removing the bottom case.
MacBook Air (2018–2020, Retina): LCIs near the battery connector and along the logic board edge. Requires pentalobe P5 screwdriver to access.
M1/M2/M3/M4 MacBook Air and Pro (2020–present): LCIs near the battery connector, adjacent to USB-C ports, and near the fan (Pro models).
Important Caveats
LCIs can trigger from humidity in extreme conditions. Johannesburg’s summer humidity (December–February) can occasionally cause borderline triggering. Conversely, LCIs do not trigger from every spill — a small keyboard-level spill may corrode components without reaching the indicators.
The Second-Hand MacBook Buyer’s Water Damage Checklist
If you are buying a used MacBook in Johannesburg — from Gumtree, Facebook Marketplace, Cash Crusaders, or a private seller — checking for liquid damage should be your first priority.
Before Powering On
After Powering On
For high-value purchases, our from R599 pre-purchase inspection at our Hyde Park workshop includes a logic board microscope examination.
When Silent Corrosion Becomes Catastrophic
Week 1–2: Minor symptoms or none. The owner assumes the spill was harmless.
Month 1–3: Intermittent issues begin. Occasional charging failures, random trackpad clicks, a sticky key. Often dismissed as "quirks."
Month 3–6: Corrosion spreads along copper traces. Symptoms become frequent and severe.
Month 6–12: Catastrophic failure. The MacBook will not power on, shows no display, or enters a boot loop. Repair cost has typically tripled.
A client from Sandton brought in a 2023 MacBook Pro M2 Pro that had suffered a "tiny splash" eight months earlier. Under our stereo microscope, we found corrosion across four circuits — the charging IC, display backlight driver, DRAM line resistors, and Thunderbolt controller. Total repair: R9,800. Had she brought it in during Week 1, the ultrasonic clean alone (R1,800) would likely have prevented all of it.
What to Do If You Spot the Signs
For what to do after a fresh spill, read our first aid guide. For pricing, see our 2026 cost guide. For the full repair process, visit our pillar guide. If repair is needed, our repair vs replacement guide helps you decide. Learn more about our liquid damage service and logic board repair.
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Frequently Asked Questions
Q: Can I check the LCIs myself without opening my MacBook?
On older MacBooks (2013–2015 Retina), you can see some LCIs through the bottom case vents with a bright torch. On 2016+ models, the LCIs are only visible after removing the bottom case (pentalobe P5 screwdriver required). We recommend a professional from R599 assessment.
Q: My MacBook was splashed weeks ago but seems fine. Should I still get it checked?
Yes. Silent corrosion can progress for months without obvious symptoms, then cause catastrophic failure. A from R599 assessment at our Hyde Park workshop can identify hidden corrosion before it spreads.
Q: Can liquid damage be repaired if found months later?
Yes, but the cost increases significantly. Prompt treatment (within 4–6 hours) typically costs R1,800–R2,400. Delayed cases often require component-level logic board repair at R4,500–R12,000.
Q: Does AppleCare+ cover liquid damage?
AppleCare+ covers accidental damage with an excess fee (approximately R1,299 per incident). However, Apple replaces the entire logic board. For minor to moderate damage, independent component-level repair at ZA Support is often more cost-effective.
Q: How can I tell if a second-hand MacBook has water damage?
Use our 10-point checklist: smell the keyboard, check ports with a torch, inspect screws, test every key, test both USB-C ports, check battery condition, test speakers, verify Wi-Fi and Bluetooth, and run Apple Diagnostics.
Q: Can humidity alone trigger the Liquid Contact Indicators?
In extreme conditions, yes — Johannesburg’s summer humidity can occasionally cause borderline triggering. A fully red/pink LCI combined with physical signs reliably indicates liquid exposure.
Q: What is the most common sign of hidden water damage?
Intermittent charging issues. The USB-C charging IC is one of the first components affected because it sits near the port where liquid enters.
Q: How much does it cost to diagnose water damage on a MacBook?
Our comprehensive assessment is from R599. This includes disassembly, LCI check, stereo microscope examination, component-level diagnosis, and a detailed written quote. From R599 assessment applies to the repair itself.
Contact ZA Support on **064 529 5863** (WhatsApp) or book online.
