I have a MBP 13" A1425 that keeps powering down either using just battery or via main power. I've formatted SSD and now I can't even install new system on the SSD as the MBP keeps powering down midway through installing. I've booted up via an external hard drive and if I unmount the SSD via disk utilities, I seem to get a stable system without the MBP powering off suddenly. Can anyone give me any clues as to what could be causing my problems. Only thing I can say is maybe it's the SSD, I've even tried partitioning the drive installing on to one part of partition.