@ webmany
Can you just confirm that you have now seen the insert disk screen at some point?
I ask because I have *never* been able to get the insert disk screen on an A4000 unless a healthy and correctly fitted CPU card is present. Has anybody??
If you have seen the screen then that is good news. If not, I would suggest doing your tests with only the CSMK3, PSU and 2MB RAM connected to the motherboard until you get the insert disk screen. Then when you get the screen add on the floppy and the HDD. After which it will be a case of sorting out your software as stated.