This phone started rebooting frequently about 30 hours ago. Sometimes it won't power back on right away. Being plugged in makes no difference. It's sometimes rebooted mid-boot. Am on the PFD program. Haven't seen an update applied for at least a few days before this started happening. No new apps. I went through a factory reset earlier today but it's continued to happen in the last few hours. Any bright ideas what I could try at this point?