If you have a SimpleTech SimpleDrive connected to your computer and you're experiencing problems with the external hard drive, there may be several reasons why it's malfunctioning. Troubleshooting your computer can help rule out common problems and the possibility that the hard drive may be defective. If you recently purchased the device and suspect there is something wrong with it, return the defective drive to SimpleTech or the reseller for a replacement. Incompatible USB Port Problems
SimpleTech SimpleDrive plug and play options makes it easy for you to connect the device to your computer. But you may encounter problems if your computer's USB (Universal Serial Bus) ports are not compatible with the external hard drive. Make sure your ports are powerful enough to operate the drive. USB 2.0 ports are recommended, but if you're using an older computer with 1.0 ports, the hard drive will function much slower or you may receive an error message that the device is not compatible with your system. b> Missing External Drive Letter
If you're unable to find the SimpleTech external hard drive's letter on your desktop after you have installed the drivers for the device, it's possible that the external drive may be assigned to another drive. Sometimes, the hard drive is assigned to a network drive and you may need to manually change the drive's letter in Disk Management. b> SimpleTech SimpleDrive Incorrectly Formatted
b> SimpleTech SimpleDrive is normally pre-formatted for Windows NTFS (New Technology File System), but Mac users may need to copy the backup software and reformat the external hard drive for FAT32 or Mac OS to be able to use the external drive. If the external hard drive is not formatted correctly for your system, it may not function or work properly. b> External Hard Drive Inaccessible
If you receive an error message that says "Drive Inaccessible," the SimpleTech SimpleDrive may not be able to read the service area of the platter. If the external hard drive emits a loud or abnormal sound, this could mean the device is failing.
Test the drive on another computer to see if it is working properly. Otherwise, the external hard drive's surface area may be damaged or corrupted. Replacing a Defective Hard Drive
You can return a defective hard drive that is under warranty to SimpleTech. The manufacturer will exchange the device if the seal is not broken.
But if you break or tear the seal on the case, any warranty claims will not be accepted and the device will be returned back to you. SimpleTech will only accept the device if you contracted a commercial data recovery company to retrieve critical data from the external hard drive and the seal needed to be broken. Before returning the defective drive, you will need to secure a RMA (Return Merchandise Authorization) approval number from SimpleTech and furnish any invoices or documentation regarding the data recovery company's services
or if its a usb external drive you might need a usb 3 card installed on your computer your computer might not have enough usb output power USB 3 card will provide more power when needed to the device to gain maximum throughput and conserve power when the device is connected but is idling http://blog.premiumusb.com/2010/09/usb-2-0-vs-usb-3-0/
these can be purchased on Ebay cheap and easy to install http://www.ebay.com.au/itm/PCI-e-PCI-Express-USB3-0-Card-new-NEC-720200AF1-chipset-/330608109325?pt=LH_DefaultDomain_0&hash=item4cf9c7670d
for roughly $9 or $10free postage Hope this helps.