From the numbers I am seeing, calculated on the total number of iPhone 6/6plus sold, less than 0.05% for this problem. The average failure rate for most phones is around 3.7% from all causes, not counting broken or cracked screens. The Apple rate is around 2.4% not counting broken or cracked screens. This isn't even a nose pimple on that body of failures for that model of iPhones.
Interesting article from an Android centric website on the comparison of failure rates of all Android phones v. all iPhones over the lives of those cellular phones:
Android phones failed at higher rates than iPhones in Q1, study shows, these are the worst offenders
13 May 2016, 05:06, by Daniel P.
Source — PhoneArena.comAndroid phones failed at higher rates than iPhones in Q1, study shows, these are the worst offenders.
Android phones have been flooding the world for the last couple of years in all shapes, sizes and price points, so there is little wonder that they are failing at higher rates than the pricey, limited iPhone editions. Still, the latest phone failure rates study from the Blanca Technology Group comes to draw that conclusion in the form of a nice graph, so no complaints.
What the research firm found out is that the failure rate for Android devices was 44 percent, compared to 25 percent for the iOS-driven gear. Moreover, further analysis shows which Android phones have broken down most often in the previous quarter. That would be a few former Samsung flagship editions - S6, S5 and S6 Active - again no wonder, given how popular they are, but the Lenovo K3 Note sticks like a sore thumb in this graph, indicating some underlying problems with the handset. Ditto for the 3rd generation of the Moto G.
These two are budget handsets, so the failure rate of Samsung's mid- and high-end phones would be more concerning. Until you look at the actual percentage of failed units, that is - the 6-7% tally can hardly be called alarming. Unless you are in the failed device owner category, that is. As for Apple, out of the 25 percent of failed iOS devices for whatever reason, it's the iPhone 6 and the iPhone 5s models with the highest mishap rates, or those with the largest ownership base among iPhone fans.
