WD5000D032-000 suddenly won't mount, pulsing sound coming from power supply

Hi, 

I restarted my Mac and my external HD won’t mount. The light in the center lights up, but it doesn’t sound like the disk is spinning. Also, I’ve noticed a pulsing sound coming from the small plastic rectangular shaped box that says “Asian Power Devices, Inc.” can anyone tell me if it sounds like the power supply has gone and not sending enough power to spin up the drive or, is the disk is fried, and if so, where can I go for data recovery?  Please help.

Thanks, 

Michael

Did you overvolt the drive with the wrong adapter? Did you drop it?

If you are prepared to void your warranty, remove the drive from its enclosure and connect it directly to a computer motherboard. Alternatively, install it in a third party enclosure.

A common problem is a shorted TVS diode, in which case there may be an easy no-cost DIY fix.

No, i’ve used the adapter that came with it. What is a TVS diode?

TVS = Transient Voltage Suppression.

The following article should help you identify the components:
http://hddscan.com/doc/HDD_from_inside.html

Turns out it was a bad power supply. @fzakbar, you were right! Thanks!