Google Nexus 5 — Phone won't power on, buzz/vibration

Hi, my six-month old (still under warranty) Nexus 5 isn't powering on. The only thing it does when it's connected to charger is buzz/slight vibration and the Google logo comes on for a second and this keeps repeating until phone is disconnected from charger. We can't get the phone to power on so some troubleshooting suggestions won't work since we can't get onto the phone. Have called Google. All their troubleshooting pointers don't work. Said they would replace... with refurbished phone... which I will not accept. They will not replace with a new phone. Totally unsatisfactory and have spoken to/emailed with SIX different people since Saturday because they keep 'passing the buck'. Has anyone had this problem with this phone? Any solutions? I appreciate your help! My son wants his phone back!! Thank you!

— modified on Feb 5, 2015, 3:03:37 PM