Liquid Contact Indicators

Liquid Contact Indicators for MacBook Air (M1, 2020

The top case includes spill sensors called liquid contact indicators (LCIs) to help discover accidental damage to the computer. The sensors are visible only when the bottom case has been removed. The LCIs are visible with an ultraviolet flashlight (UV) when they have come in contact with liquid, such as an accidental spill.

How to Read Liquid Contact Indicators with Ultraviolet (UV Light

How to Read Liquid Contact Indicators with Ultraviolet (UV Light

MacBook (Retina, 12-inch, 2017), MacBook Air (Retina, 13-inch, 2018 and 2019), MacBook Air (M1, 2020), MacBook Pro (2018, 2019, and 2020), and MacBook Pro (13-inch, M1, 2020) contain spill sensors called liquid contact indicators (LCIs). LCIs help discover accidental damage to the computer. They are black, and liquid contact is only visible with the use of a UV light. LCIs appear black under normal light and glow blue when highlighted with a UV light. They turn pink or produce a pink halo when they come in contact with liquid.

Note: MacBook Pro (15-inch, 2018 and 2019) also has one LCI that appears white and turns pink when it comes in contact with liquid.

Important: A triggered LCI is not the only evidence of liquid contact. Be sure to inspect for corrosion or liquid residue during a quick check or repair.

No Liquid Contact:

• LCI without UV light
• LCI with UV light

Liquid Contact:

• LCI without UV light

• LCI with UV light

Safety Information:

Caution: UV LCIs illuminate with the use of the Apple-approved UV light (923-01604). Follow safety precautions when using this tool:

• Do not remove the warning labels on the UV light.
• Do not shine the UV light in anyone's eyes or face.
• Avoid repeated exposure to the UV light.
• If a different UV light is used, safety glasses and gloves must be worn to avoid excessive exposure.

The following images show the general location of LCIs in a MacBook computer.

Procedure

Note:

• Ultraviolet LCIs are black. The black LCIs blend in with the rest of the computer. When in contact with liquid, the LCIs may swell and become easier to identify.
• When using the UV light, hold it 12 to 14 inches (30 to 35 centimeters) from the computer and shine it at an angle of 15 to 75 degrees.

Warning: While the UV light is shining, do not hold it close to your face or bend your head down to look closely at the LCIs.

• Press the power button on the UV light. 1.

• Check the color of the LCI. Blue indicates an LCI that has not been triggered. A pink LCI or a pink halo around the LCI 2. indicates that it has been triggered. Refer to visual examples at the top of this article.