Apple Hardware Test and Disk Utility shortcomings
Is it possible for Hardware Test and Disk Utility to not recognize a hard drive that is failing?
I am troubleshooting my nephew's iMac Late 2013 with Fusion Drive. It's a Mac I'm very familiar with because I gave it to him last October, 2019 for schoolwork. It's had 3 logic board replacements (had 2 defective ones). Logic board finally good 2 months ago. Now, the iMac is not booting up. Gets as far as Apple logo and no progress bar.
Ran Apple Hardware Test; no issues found. Disk Utility Repair; status appears to be OK. Meanwhile, I can hear some very faint clicking noises coming from the hard drive. My guess is it's on its last legs.
Trying to reinstall MacOS from recovery; took awhile to get to the install screen but I'm there now and says it's installing. Red flag = says 35 hours to install??? I cancelled.
Booted up from and SSD backup. Everything is working fine; system is even "snappier". I'm 99% sure the Fusion Drive is kaput.
Anyway, back to my question. If Apple Hardware Test can't diagnose anything wrong -- cause it never diagnosed the 2 defective logic boards either -- what good is it as a troubleshooting tool and how are we to rely on it for useful information?
Ugh, just my rant for the day. Thanks for listening! LOL.