Hello. I am trying to "Factory Restore" a MIDI guitar processor from the 80s called a Roland GP-8 with a .mid file. I am doing everything the manual says to do, and I have done that with two separate GP-8s but nothing happens. I have used software on both Mac and PC, but I am getting nothing. The cable lights up when the data is transferred, but the processor doesn't do what it's supposed to. I am at the end of my rope! Thanks.