I powered up my PS4 tonight for the first time in months. The Dual Shock 4 appeared dead and pressing the PS button only made it blink white for a short time before briefly turning amber and shutting off. I tried plugging it into the cable if it was a dead battery issue but that did nothing. Stuck, I went online and found this solution.

 http://community.us.playstation.com/t5/Consoles-Peripherals/PS4-controller-won-t-charge-and-won-t-turn-on-Please-help/m-p/45263256#M173337 

Here's the info should the page disappear:

I found this and it's the only thing that worked.

"A In Depth Guide to fixing DS4 Connection Issues.
1. Put your DS4 in pairing mode by holding PS button and share simultaneously. The light bar should begin to flash white.
2. Connect the DS4 to the device via Bluetooth on any of the following devices. ( PC, Android, PS3 )
3. Disconnect the DS4 from the paired Bluetooth device. Make sure you disconnect directly from the bluetooth device. Once disconnected locate a pin or a small narrow object and push into the reset hole on the rear of the DS4. Hold in place for 10 seconds.
4. Connect the USB cable to the DS4 and proceed to power on the PS4. Once the system has loaded to the login screen it will ask you to press the PlayStation Button. This will iniate pairing between the DS4 and PS4. The DS4 should now be fully operable.
Make sure to follow steps exactly for best results."

I tried resetting via the tiny hole on bottom but didn't work. Not immediately anyway.
Things did change when I enabled bluetooth on my Samsung S4. Almost immediately the controller blazed that familiar blue light and although unable to pair with the phone, the PS4 that was in rest mode came back to life and after a few seconds was paired up and ready to go.

Saved the day, for sure. 8)