Well !!! Happy 2014 to all as i see this i have the same issue with Casalla and everything that i have read till now as Jaclaz say pointing to grounding tho i dont understand something vital.... to my case i need to put the black wire from my converter not direclty to my HDD ground pin but i need to put it somewhere else ? in a spare battery at minus ? this is step 7# I will repeat myself, you NEED a (black) wire connecting: the Hard Disk Drive "Ground" pin the converter "Ground" or 0V pin or connector or wire the (standard PC) Power Supply black wire OR if a battery is used, the - (minus) side/pin of it OR if a separate Power Supply is used, it's black wire or 0V pin or 0v/-(minus) connector or anyway wire marked 0v/-(minus) or connected to anything marked 0v/-(minus)/GRN/GND/GROUND thanks