Make sure monitor is setup to the right settings. Sounds odd but if you see no kickstart screen it may be on the wrong setting or inputs plugged in wrong. Sounds stupid, but I have 4 different monitors and I actually did this with an Amiga 2000 and found that no Display (stayed dark Grey) and after 45 minutes messing with it changed the monitor setting then bam there was Kickstart screen. After that then you can assess if drive is bad or disk is bad if that is the case