iMac (27-inch, Mid 2010) Symptom Charts — Mass Storage 70
2010-09-09
Mass Storage

Hard Drive Not Recognized

Unlikely cause: LCD panel, power supply, fans, speakers, camera, microphone
Quick Check
Symptoms Quick Check
Drive Not Recognized
Drive No Boot
• Flashing Question Mark
• Boots to Grey Screen
• Boots to Blue Screen
• Boots to Prohibitory Symbol
(Review kBase #HT2674: Intel-
based Mac: Startup sequence
and error codes, symbols)
1. Use a known-good mouse. A stuck mouse button
will not allow boot.
2. Boot from Install DVD. Use Disk Utility to verify
S.M.A.R.T. status of internal drive(s).
3. Use Disk Utility to repair Mac OS X on disk.
4. Verify that user’s data is backed up and that user
authorizes erasing disk and reinstalling software.
5. Use Target Disk Mode to mount user’s drive on a
known-good computer. Use Disk Utility on host
computer for Quick Checks 2 through 4.
6. Identify if system is shipped with one hard drive,
or with a second SSD drive option (Mac OS X
boot volume setup may dier in that case)
Deep Dive
Check Result Action Code
1. Boot from Install DVD and run
Disk Utility. Verify if user’s drive
is available for Disk Utility to
repair.
Yes Go to step 2.
No Go to step 5.
2. Run Disk Utility ’s “Repair
Disk” function and verify if it
completes successfully.
Yes Go to step 3.
No Go to step 4.
3. Reboot computer. Verify if
system boots successfully and
that Disk Utility “Verify” function
reports no errors.
Yes Data error. Issue resolved.
No Go to step 4.
4. With user’s permission, erase
internal drive and reinstall Mac
OS. Verify if installation process
completes.
Yes Go to step 8.
No Go to step 5.