by So a friend of mine calls me to tell me that the hard drive on his Dad's mac had failed and was wondering if there was anyway to recover the data as there were no backups. My answer was 'it depends on the failure mode'. Failure modes of a hard drive are:
If the drive failed because of an electronics problem, then you may get it to work by getting some circuit board cooling spray, cool down the circuits and see if that helps out.
If the drive failed because the lubricant on the drive spindle failed, then dropping the drive from a foot or so on to a table top may jar the spindle enough so the drive motor can spin it again.
If the drive failed because the data on the drive is corrupted, then a drive recovery software may be able to recover the data.
Any way, a few days after I told him this, I got this reply: "My dad took his iMac to the Apple store, they tried everything & basically said the drive was dead. With your encouragement I had him bring it to me. OMG, to get to the HD on a G5 20" iMac is a challenge to say the least. But got it out & fortunately years ago I had bought a universal drive adapter, and I was able to figured out how to set it up. After connecting it I got nothing. So I picked up the drive & dropped it a couple times. A message appeared not long after about "Drive Repair could not….blah, blah, blah" — so I clicked off it. I happened to be on-line buying something else & was distracted for 3 or 4 minutes and all of a sudden, BAM!!! Up pops an icon on the desktop, like a external HD. I was able to get 100% of everything!! Whoo-hoo."
Epilogue: His Dad is now setup with an new internal disk, an external harddisk and Time Machine.