Dell xps 14z won't turn on

How long ago did you spill water on the system? Have you tried a reset? Unplug the adapter and disconnect the battery. Now press and hold the power button for 30 seconds. Reconnect everything and try to boot again.  If that does not help then remove the CMOS (coin cell) battery. Leave it out for 15 minutes (Intel recommends 30). And considering the water damage it could be corroded so replace the battery after 15 minutes. Then try a boot again. The problem is that it is possible the battery connections got wet and over time have corroded, assuming that the spill happened some time ago. Either the battery, adapter, DC jack, or the motherboard is bad. And with water damage, no matter when it occurred, anything is possible.

Thanks, JOcean.

Water spill happened on Thursday.

The damage is on built in keyboard.

On Friday, I was able to use the laptop normally with the help of external keyboard.

So, then 3 days later on Monday, when I turned on the laptop, the screen showed "battery low".

Battery low issue has been quite long since several months ago.

I tried reset, that's unplugging adapter and battery then press and hold power and so on.

It didn't work.

I haven't tried the CMOS battery. Will try next.

I'm not very sure but suspect the difficulty to turn on laptop is related to battery because the problem only started after I turned on the laptop without plugging in the adapter.

Screen last showed "battery low" before laptop totally cannot be turned on.