Re: I got OTA update alert for Lollipop on my nexus 4, but after failed attempts of download it is g
1) If the phone has ever been rooted, or you're running any custom ROM, the update will fail. It's either that or risk bricking the phone. (Even if you unrooted, if you changed anything while rooted, or there are still "leftovers" from rooting, the update will fail.)
2) If you check for an update less than 24 hours after the last one, you won't find any. You have to either wait 24 hours between tries or change your phone's clock so it thinks 24 hours have passed.