macbook air trouble booting, dead keyboard

Hi,

You'd better off contact Apple support or make Genius Bar reservation to talk about the keyboard.

I think your MacBook Air has hardware related issue, though I just wonder if you connect external keyboard to your MacBook Air would works.

A common issue I have seen is the Trackpad Cable (or IPD Flex Cable) at the Trackpad can sometimes become damaged by just the smallest amount of liquid seeping past the top of the Trackpad. You can check to see if there is any corrosion on this part of the cable or the connector on the Trackpad itself which can be hard to see, but sometimes you can make out a bit of corrosion at the edge of the trackpad connector.

Even if the liquid indicators are all normal, it does not mean liquid hasn't hit some of the circuitry. You just have to look for liquid residue and corrosion. Sometimes this can be very difficult to see and usually requires using a magnifier. A lot of times the I/O Cable connectors on the I/O Board and Logic Board can get damaged by liquid. If the inside of the connectors have any corrosion or issue, then the cable and the part it connects must both be replaced since it is impossible to clean those connectors.

FYI, right near the power on pads are a pair of pads for the SMC reset. The SMC reset pads are located 90° around the chip from the power on pads. I forget which set of pads is for which feature. One set of pads is located between the WiFi card and the tiny chip near the edge of the board. The other set of pads look identical and are located 90° around the same small chip (to the right of the small chip if the vents are at the top away from you). The pads will be the ones at the very bottom left corner of the red square showing the power on pads in the picture from the post here.