Thanks Blue,
I went back and took another look at the thread and found the the links to the pics at the bottom of the post.
Checked the m/b and no mod.
Had already tried the jumpers at single drive. Not sure there is a lot of point trying just master as the HD's are acting exactly as posted in the the ASSY# thread. Format fine but fatal errors at start up or check.
decision, decisions.... Do I look for another 705n/4100 with the mod and no drives or plumb for a Dell 725n, which I believe is an OEM 4500.
Oh looks like I am running the Snap version of the OS my current 705n details in the signature.
Thanks for your help on this.
Cheers