If your Cobalt SM 6 phone is corrupt or bricked. Download Cobalt SM 6 stock firmware from here. To get it back to a working condition again.
All you have to do is simply download the below-given Cobalt SM 6 firmware files and tools on your PC. And then follow the given instruction to install the Stock ROM on Cobalt SM 6 using SP Flash Tool. This guide is also helpful to unroot. Or fix any software malfunctioning problem.