Droid maxx reboot

[Josh Wetherill]

so i purchased my maxx in dec 2014 and it just recently started rebooting in July. at first it would just shut down on its own then turn right back on. then it shut down for three hours before i could turn it back on. after the three hour shut down i backed up every on the cloud and did the recommended factory reset. it had only done a normal reboot on its own (off then on again) a couple of times in the past month, until last night. it shut down for seven hours and wouldn't turn on till seven this morning. do i just need to get a different phone or i there something else i can do? as in reinstall the verizon droid system? or just another factory reset and reinstall apps one at a time?