WD External Drive won't mount...shows in disk utility

Our Western Digital - My Book Studio running on Mac Pro refuses to mount.  It shows up in Disk Utility.  We’ve tried several power supplies, several mac pros and several firewire and usb cables.  We ran verify disk and Disk Warrior.  Still will not mount.  Any one have a solution?  Thanks.

Hi there, if it won’r mount even after trying DW and DU, then what if you reformat it after trying a data recovery software such as TestDisk? It is what I would do if I were you!!