Some good info about restoring the MBR in that thread, but if I read the OP's msg correctly it sounds like the drive isn't getting power. If you're not getting a power light where you were getting one before those hints probably won't help.

Probably a pretty good idea to try & salvage the drive. If it's one of the WD "My Book" series they're a bear to get open. I actually took one apart yesterday which had a bad drive using these instructions:

I'd pickup either another external SATA case or a temporary USB-SATA widget & see if it'll come up.