laCie d2 disk invisible with mountain lion OS

[shawuruo]

My LaCie d2 and WD external hard drives are invisible since I upgraded to mountain lion OS. I tried to restore/ verify them in Disk Utilities; both apper in grey and error message 'disk not mounted' appear. Both connecetd to mac via USB. Any suggestions on how to rectify this?

[chscag]

Need some specs on your Mac, which one do you have - year and model? Also, how about other devices when plugged into the USB ports, are they working OK?

[shawuruo]

macbookpro 2009
other devices, in fact another lacie edicated as timemachine, connects via usb no prob

[chscag]

Can you tell us how the LaCie and WD external drives are formatted? In other words, what file system format are they using and when you upgraded to ML, which version of OS X did you upgrade from?

[shawuruo]

Both were formatted on earlier OS on the same mac, i think it was Leopard

[chscag]

Thanks for posting back. Both drives should appear if they're not damaged or defective in some way. You said they were used with your same Mac when it was running Leopard? How did you upgrade then from Leopard to Mountain Lion? You had to at least be running Snow Leopard 10.6.6 in order to upgrade to Mountain Lion.

[LaCieTech]

I hate to over simplify, but it needs to be covered. Start here, then consider more complex steps.

Physical troubleshooting.

The symptoms indicate there is a problem with the drive, how it is connected, or with the computer used for troubleshooting. The next best step is to change physical variables, and find a simpler problem than a broken product.

~ Change the data cable (USB, FireWire, Ethernet, etc.) A failure in the cable can cause this issue.

~ Change the external power supply or cable. If a different LaCie product is available, borrow the power cabling from that unit to see if the problem is in that component. On drives that are powered via USB or Firewire, try using the included power sharing cable and connect it to a second port.

~ Change the computer you are using. Computer problems can manifest themselves in many ways. Even if the computer appears to be working properly, this is a worthwhile test.

If you have the same results on another computer with both drives I would have to assume both drives were connected to your computer during the upgrade and the upgrade corrupted the data. ~TE

My LaCie d2 and WD external hard drives are invisible since I upgraded to mountain lion OS. I tried to restore/ verify them in Disk Utilities; both apper in grey and error message 'disk not mounted' appear. Both connecetd to mac via USB. Any suggestions on how to rectify this?