I have a MacBook Pro PCB that has lots of yucky, gooey and sticky grime from a spill that thankfully didn't damage the board. I would like to clean the PCB thoroughly, but I fear turning the liquid contact indicators (LCI) red and raising eyebrows at AppleStore in case I take my machine in for paid repairs.

I've read about repair shops using ultrasonic cleaning using water mixed with Branson Ultrasonic Cleaning Solution to clean PCBs, but it is unclear whether it sets off the LCIs. Does it set them off?

I'm considering using a soft brush and denatured alcohol, which is around 90% ethyl with some methyl additives according to MSDS. Do I need to be extra careful to avoid having alcohol contact the LCIs?

  • 1
    \$\begingroup\$ Isn't opening it voiding the warranty anyway? \$\endgroup\$
    – Eugene Sh.
    Feb 22, 2019 at 19:37
  • \$\begingroup\$ This is a bit unclear to me. After a spill, you are not worried about water damage from the spill but are worried about water from the cleaner to clean up the spill? I can only assume that you are referring to cleaning the OUTSIDE of the laptop? Not opening it up and cleaning the board? If that's the case just mist a cloth with alcohol and wipe it down. If the cloth is dry enough it would go anywhere. I don't think you're supposed to have extended skin contact with methyl alcohol, wood alchol, or denatured alcohol. I seem to remember an MSDS saying to seek medical attention if that happens. \$\endgroup\$
    – DKNguyen
    Feb 22, 2019 at 20:58
  • \$\begingroup\$ @Toor, Thank you. I have a ambigous pronoun in my sentence. I will update the question. \$\endgroup\$
    – user148298
    Feb 23, 2019 at 16:24
  • \$\begingroup\$ *I obviously meant to say "wouldn't go anywhere" \$\endgroup\$
    – DKNguyen
    Feb 23, 2019 at 18:40
  • \$\begingroup\$ When a company puts "warranty void if broken or removed" sticker on, they are actually breaking the law. ftc.gov/news-events/press-releases/2018/04/… \$\endgroup\$
    – whitis
    Sep 8, 2021 at 6:21

1 Answer 1


Alcohols are hygroscopic, meaning they will readily absorb water. It is unlikely the alcohol you have is anhydrous, so I would not advise getting it near the indicators.

I suspect anhydrous alcohol would still change the LCIs.


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