My Book Home not detected by iMac

[onefinesunday]

Just tried the help from this thread:

http://wdc.custhelp.com/cgi-bin/wdc.cfg/php/enduser/std_adp.php?p_sid=T*hSUvfk&p_faqid=505&p_created=1030579863

It’s still not working.

The HD does not show up in Disk Utility too. Previously it did before the problem occurred.