Simpletech external 500GB HDD with external power not detected

Is this a new one or have you used it for some time? If it is a new one, it might not be getting enough power to work.
If you connect it through a USB hub, disconnect the hub. Connect the HDD directly to the computer and see.
If it doesn't work, find a USB cable with two USB jacks on one side. Connect both to USB ports at the back of the computer (and of course, connect the other end to the HDD) and see.

Best of luck!

You may have a power supply that is defective or is failing. Try another power supply, 12V, 2A, center pin positive.

If you get no joy using the Troubleshooting Guide then try this...
You will need to check You Tube to find a Dismantle on your product and follow the step guide on here, the procedure should be similar.
Check 1st that your External HDD has an P.C. internal HDD inside, from You Tube, before dismantle of your External HDD. Connections for an Internal Laptop HDD may have same connections as P.C. not sure though.
Once your happy that it has continue reading and follow the step guide on the link below.
My neighbour has the Seagate FreeAgent Desk 500GB, and in under 2 weeks it started to beep and was not recognized by any Laptop or P.C. if this is the same for you with any FreeAgent Desk series ( not GO series, different procedure for GO products). You maybe in luck click this link, you may have to register in the forums to view thread.... http://www.yo-lid.co.uk/forum/viewtopic.php?f=32&t=84 Thread can be found in 'Technical' under 'General Technical Issues',
Only attempt this option if you have important information saved in it, you will find that you will be charged by your product makers for retrieval of any information saved on your product.
Thumbs up please if it's any use to you Thank you.

If you get no joy using the Troubleshooting Guide then try this...
You will need to check You Tube to find a Dismantle on your product and follow the step guide on here, the procedure should be similar.
Check 1st that your External HDD has an P.C. internal HDD inside, from You Tube, before dismantle of your External HDD. Connections for an Internal Laptop HDD may have same connections as P.C. not sure though.
Once your happy that it has continue reading and follow the step guide on the link below.
My neighbour has the Seagate FreeAgent Desk 500GB, and in under 2 weeks it started to beep and was not recognized by any Laptop or P.C. if this is the same for you with any FreeAgent Desk series ( not GO series, different procedure for GO products). You maybe in luck click this link, you may have to register in the forums to view thread.... http://www.yo-lid.co.uk/forum/viewtopic.php?f=32&t=84 Thread can be found in 'Technical' under 'General Technical Issues',
Only attempt this option if you have important information saved in it, you will find that you will be charged by your product makers for retrieval of any information saved on your product.
Thumbs up please if it's any use to you Thank you.

Hello there...

Looks like your HDD is having mechanical problem, this could happen due to a shock (dropped or bumped maybe?) which can cause your HDD I/O head loose from its track.

My advice is start backup you important data when you can access you HDD and prepare a HDD replacement.

hope that helps... :D

contact FRYs or the HDD manufacturer . The HDD may be bad !

You're not missing any step at all, because with SATA hard drive if its really working your computer should
automatically detect it and since this hard drive suddenly stop working there's a possibility that its already
fried but if you want you can try this hard drive again to a different computer and if still not detected by
second computer its already dead.........

Actually the simpletech dosent need power adapters so u dont need to check for adapters and if you are connecting to usb2 port the power should be embaded so just connect the single usb cable not the both if using usb 1 then connect the both usb cable to usb port if u have already done this please try to change the usb cables wich is connecting the hdd and the pc something wrog in the cable for sure
thanks

well..you can 'see' it on the my computer, right? welll, then perhaps you'll check the usb cable, no?

Is the drive running when connecto to power ans PC?
Try it on another PC.
Check the power supply if it is operated from an external power supply.
It it is self powered via the USB then this is a possible problem- the PC power supply cannot cope - Removing other USB devices may help here