[Kepster]

Ok I was rooted running cyanogen 7 nightly but need to send my evo back to sprint so I unrooted and installed stock 2.2 then updated OTA to 2.3.3 thought I was the bomb until I discovered that I didn't have a recovery anymore, because I was using clockwork mod before. I'm Not rooted anymore so will I be able to exchange under warranty or is there away to flash stock recovery back to phone. When I attempt to go in recovery I get the red triangle, I pull the battery and it will boot back to 2.3.3, any help would be greatly appreciated