What problems can be expected with these drives. What symptoms should we be looking for?
Apple has never said anything beyond that they "may fail under certain conditions."
The program seems to cover also iMacs with 3TB Fusion drives, although this is not stated on the support pages. I will bring in mine later this week and keep you posted on the results.
Oh, interesting - I guess that would make sense, if the hard drive portion of the Fusion drive was the same mechanism.
And indeed. At the appointment with the Genius Bar in Amsterdam last Wednesday the genius guy on duty started the iMac via network. They have a bunch of diagnostic tools ready that way. Within max 2 minutes the first tool ran into the message Failed - bad sectors found. Then he ran another tool to check other components like RAM and gpu. No further errors found.
The dialog boxes of these tools where MacOS9-like by the way. Nostalgia!
Of course the iMac had to stay for repair. Indicated is 3 tot 5 days. However, today I simultaneously received an e-mail and a phone message that the machine was ready for pick-up, so that's exact 49 hours.
My Time Machine back-up is running a restore now; this may take a while, this model iMac is USB 2.0.
By the Grace of David Danian of 1Password who read one of my logs after I had difficulty with a backup (guess why) and let me know he thought my iMac Fusion Drive would fail eventually.
At first Apple denied the problem. But with David's log as evidence and the persistence of my senior AppleCare advisor who reached the same conclusion as Dave, a second look from Apple resulted in their concurrence. A replacement with a new Fusion Drive was accomplished off-site at the repair facility, and I am grateful Apple finally concurred. Also greatly appreciate Dave's excellent support. Lucky me for not having to find out the hard way/