Mac not turning on... (Again!)

"Open, remove and clean the logic board for liquid damage. Likely there will be corrosion on the bottom of the board.

Intermittent issues (as you described in the comments of @pccheese answer, is usually caused by liquid. This has probably affected some of the soldered components as well.

Check the I/O cable and trackpad cable (both ends) for liquid too, for good measure :)"

"I have a mid-2014 MacBook Pro with the similar issues described here.

Wouldn’t power on at all. Took it to a authorised repair centre. They opened it up, blew some air in, dis/reconnected a few things (unfortunately not sure exactly what), and it started working again. I took it home, worked perfectly. The next day, dead again. Took it back to the store, they couldn’t get it working for several hours, about to give up then it came to life again. They ran diagnostics on it for 24 hours and could find nothing wrong.

They said when it wasn’t working, they tried booting via the onboard power terminals and that still didn’t work, so they thing it’s logic board related rater than the top case.

Kept it in the store a few more days. I’ve just picked up again, and ‘seems’ to be fine. Will see what happens next… would love to know if anyone found out the cause."

"Its not operating system related because I blew away the Mac OS and installed a new one (Linux). It still is doing the same thing. Sometimes it will power on right away, usually right after its shut down or it wont power on at all and could take minutes hours or days before it starts again. This is only happening on Mac book air. Never had a laptop do this before and no liquids have ever been spilled on it.

Update (07/26/2019)

Battery health 1 of 2:

upower -i /org/freedesktop/UPower/devices/battery_BAT0

native-path: BAT0

vendor: SMP

model: bq20z451

power supply: yes

updated: Sun 28 Jul 2019 09:19:58 AM EDT (81 seconds ago)

has history: yes

has statistics: yes

battery

present: yes

rechargeable: yes

state: discharging

warning-level: none

energy: 25.1636 Wh

energy-empty: 0 Wh

energy-full: 52.2728 Wh

energy-full-design: 54.34 Wh

energy-rate: 13.5964 W

voltage: 7.53 V

time to empty: 1.9 hours

percentage: 47%

temperature: 34.8 degrees C

capacity: 94.7972%

technology: lithium-ion

icon-name: 'battery-good-symbolic'"

my macbook air stops powering on suddenly so what i did was visit a local tech who opened my mac, jumpstart the battery and it started working again. however it was again not powering on after a week so what i did was i bought tools and opened it myself. i disconnect and reconnect the battery, which fixed it temporarily. this is what i do every time it wont power on.