A customer complains that her desktop computer will not power on. What initial actions should you take?

Test The Components and the motherboard

Explanation:

Well, im going to assume that she turned on the pc and the screen is completely black, nothing being displayed but the fans are spinning. The first thing i would do is test the components to see if its working or not. What i would do first is test the components. I would start from the RAM, Video Card (If it has one) CPU, PSU, and motherboard. I would also take out the CMOS battery and put it back in after a while to clear the bios settings if the customer messed with the bios settings. Make sure to test the motherboard and check for physical damage (Fried Areas, blown capacitors, water Damage etc.) And if you cant find any physical damage try testing the motherboard and see if its dead or not. Also try checking if all of the cables are plugged in all the way, like a loose HDMI cable, loose psu cable etc. Also make sure the psu is connected to power

Also, this is my first answer. Yay :)  

the answer is you.