I have a working MacBook Air (2015 model) with a non-functional keyboard. Water was spilled on it accidentally which shorted everything out. A 3rd party local computer repair shop got the machine working again except the keyboard. Since then it's been used with a Logitech Wireless PC USB keyboard without any problem, putting it to sleep when done, and waking it up via the external keyboard. This has been working fine without any issue.
Recently the battery has completely drained out, effectively powering down the machine. Although the machine has been fully charged, it isn't responding to the Power button on the external keyboard.
What options do I have to make the machine boot again?