Macbook Air 2014 (820-3437-B) liquid damage help (Repaired)

[poot36]

I have a Macbook Air that I got in for repair that has had coffee spilled on it and no longer turns on.  The charger light will change from green to orange and I can do a SMC reset with the keyboard combo and the light changes to indicate a reset.  I have taken it apart and cleaned all the visible liquid damage off with a brush and then warm soapy water in a ultrasonic bath.  It made no difference.  I have confirmed that I am getting all the G3 Hot rails and that they are in spec.  The PP1V2_S3 rail and the PP1V05_S0 briefly turn on when the charger is plugged in and the battery is disconnected (the battery is dead as the client left it in a closet for 1 year after the spill) and then turn off.  When they do come up they are at the correct voltage (checked with a scope).  What would be the next thing to start measuring?

[coromonadalix]

a complete visual inspection would be good,  not just measuring stuff,  you may have corroded parts or ic's   etc ...

[tooki]

Left for a year after the spill? RUN. Coffee is acidic, and after a year, part of which was with residual battery power present, there is guaranteed to be corrosion damage.

[poot36]

I have given it a quick visual inspection and there are some laces that look questionable but test fine.  I will have to clean the brown rust like substance off the inductors though.

[tooki]

A “quick” visual inspection isn’t going to show you the problem areas, which are where capillary action kept them wet longer, like under chips.

[poot36]

I have ordered one of the cheap usb microscopes so hopefully it will get here by the end of this month.  I am a bit concerned because I did have some corrosion around the CPU vrm and the side of the CPU that has the PCH on it.  Will take a closer look when I get the microscope.

[poot36]

I got it working after a good cleaning with hot soapy water in an ultrasonic cleaner.  Thanks for the help.