SOLVED!
I am so happy that I fixed my computer so I really wanted to share with everyone my method!
I have a Asus Zenbook UX303LN laptop that did not turn on all of a sudden for no reason. The power adapter & battery were working and the power light turned on, but the fan/CPU/hard drive did not so the computer did not boot up at all. I tried all the methods I found online (up to the point I was considering doing a motherboard reflow myself) UNTIL a computer friend told me this:
1. First unplug and take out the battery. Please the power key for ten seconds then plug in power adapter and try turning it on
2. If it doesn't work, then unplug again, and reseat the RAM. Then plug in and try turning on again.
3. If it doesn't work, then unplug again, and locate the CMOS battery* in your laptop. Unplug the CMOS battery carefully and wait for 2 minutes before plugging it back in. Then plug power and try turning it on.
***My CMOS was right next to my harddrive and looks like a black round button that was wrapping in black tape. It had "KTS XXXXX 3.0V" written on it. The 3.0V helps you verify that this is the CMOS battery.
Step 3 worked for me, so if you are running into the same issue, I hope this method can help you too!