I had a similar experience yesterday. I left the key in the accessory position all day and I needed a jump. I hooked up the cables and heard a pop and my cluster went blank. I shut the bike off checked the fuses and still nothing. I don't know if this is a coincidence but I unplugged the relay above the fuse box and waited a minute, plugged it back in, jumped it and was on my way. At this point you've got nothing to loose.