Chosen Solution
Many repair technicians I’ve read recommend thoroughly cleaning PCBs using an ultrasonic cleaner with Branson Ultrasonic Cleaning Solution mixed with water. It sounds like good advise, except many Apple PCBs have liquid damage indicators. Wouldn’t the water content in the cleaning solution turn them red?
Of course it will turn the LSI red when they get wet.
It can! It depends on the cleaner. They are designed to fire off from water. Frankly, I rarely use an ultrasonic cleaner on a logic board. It’s only if the board has corrosion or a residue (liquid damage). I use a Rechargeable Air Sprayer which I load with different solutions depending on what I’m dealing with. This allows me to focus the cleaning Vs doing the whole board.
From what I’ve experienced through Apple, they don’t actually do a lot of ‘repairs’. They can definitely diagnose and replace components, but in terms of circuit level components, they just up and replace everything with a new part. They call these ‘Depot Repairs’. If you actually pay apple to fix liquid damage on your board, they will not even mess with any ultrasonic. They may not even have such machines in a Genius Bar (I can not verify that statement). So what you are asking doesn’t apply to Apple, so you have to use the thinking of, the indicator was already tripped when something was spilled. Your use of ultrasonic will mark that it was repaired properly.