The dreaded flashing Apple logo just happened to me. Yesterday, I went for a jog using Nike+ app while listening to music via JBL bluetooth headphones. All of a sudden it shut down. I powered it back on and the Nike+ app resumed recording my run. Then it shut down again! This time, after I powered it back on, the weirdest thing happened. A kernel screen came on showing programming code that filled up the entire screen.
I am running the latest iOS (iOS 8) on the iPhone 5 and latest iTunes (Yosemite). Just got back from the Apple store (Portland, OR) and the rep. told me because my phone is out of warranty they couldn't give me a replacement phone. Option A = Buy a new iPhone 5 for $260. B = Buy a newer iPhone (5C, 5S, 6, 6+) C = Beg, borrow, or steal another iPhone (I threw in the 'steal' part).
Frustrating. I have been an iPhone user since the 3rd gen. phone and never had this kernel-flashing thing happen. So much for trying to sell my working iPhone 5 32GB on craigslist to pay for an upgrade.