SMC issue or I/O Board?
I'm working on a water damaged macbook air. It had some artificially sweetened sweet tea spilled on the table around it and it found its way in.
I've thoroughly cleaned the main board, and I have it to where I can boot and use all functionality of the computer with just one catch:
If I connect the flat ribbon connector that goes from the I/O board to the logic board, the computer boots without the LCD backlight and shuts itself off before it gets to the login screen. The charge light never comes on, and the battery won't charge.
If I disconnect that ribbon connector, I can boot the machine all the way to the login screen and log into the computer. The computer has full functionality with the exception of the cooling fan running full tilt, and obviously the audio and other things that rely on that connection don't work. The battery still won't charge.
It seems like an SMC issue, but when the ribbon is not connected the backlight and kb light and all of those features work fine, even the ambient light sensor.
I'm thinking I should try replacing the IO board, but the absolute cheapest I can find it is $30, and if that's not the fix I'd rather save that cash to spend on sending the mobo out to have the SMC repaired.
Upon closer examination I found that one of the pins of the IO board connector was burned off on the IO board side. It just happened to be the 1-Wire pin for the charger control.
My "new" IO board came in today and the computer seems perfect.
Total investment under $200 including the original purchase of the broken computer.
THANK YOU to those who took the time to reply.
Is this a good question?