basically i have 2 questions about hard drives. if you plug one into a fried motherboard and power it up would this cause it to break? next is if you plug in the sata cables and power it on and then take the cables out would this do anything?
I believe that technically you are supposed to "Stop" the SATA drive before unplugging it just like a USB device. You might get away with unplugging it "hot" but I would not keep doing it forever and expect nothing to ever happen.
If you are certain the hard drive is undamaged, then there is no danger to the new system but how do you know it isn't? What SNGX1275 was saying is there is a chance that whatever caused the RAM slots to fry could have also damaged the hard drive. He isn't saying that it actually did, just it could happen.