I tired updating the software but the screen is still blank. When I put the disk in I notice the screen stopped flickering but was still left blank. When the cd ejected the screen started flickering every few seconds again. Reading that trouble shooting post it looks like that is the problem I have the navigation computer being fried which sucks. Any reason why the screen would stop flickering when the disk is put in but start again when ejected? Either way screen just stay blank. Is it just the MKIII that has this problem and if my computer is fried ,if so should I replace with MKIV?