If two drives on same cable one must be master and other slave as set on jumpers at rear of drive.
Some drives appear to work better if both set to cable select.
IDE cables have also known to fail a new one costs very little. Two types 40 wire and 8O wire. Not sure if you can fit 80 wire in place of 40 others on forum may know better.
IDE drivers may also be suspect make sure you have latwst for your board see manufactures web site.