Why does my iMac not boot up?

[iMore Question]

My early 2008 iMac starts boot up. Apple logo appears. Progress bar starts running then computer shuts down.
I tried startup with command + R. Got os x utilities window. Opened reinstall os x and got window to setup installation of os x 10.11. Clicked continue. Asked to select the disk where I want to install os x. A recovery HD is shown and when selected I'm told the disk is locked. How do I unlock it?
Also when I open disk utility and run first aid on the HD the first aid process fails. What is the implication of the failed process?
Appreciate any help. Thanks.

 

[pkcable]

8 years is a good run for any computer. I would seriously consider just replacing it.

 

[Daryle Bayless]

8 years is old, but it is probably still capable of doing what most people do with a computer, general office work, web browsing, email, etc., so long as you don't need any of the more advanced features that have come out since, such as USB 3.0 and Thunderbolt. If it can be made fit-to-task again, I would't get rid of it just because it is old.

I'm not a tech guy, but it seems to me that If you've used FileVault 2 on your internal disk, then you'd need to unlock it. It ought to ask for a password. Perhaps your admin password admin will do the trick? Otherwise, have you tried to just repartition the drive, then do a clean install?

If a reinstall doesn't do the trick, I'm not sure how much time/effort I'd invest. the newer models are awfully nice.

 

[Ariel Babalao]

My early 2008 iMac starts boot up. Apple logo appears. Progress bar starts running then computer shuts down.
I tried startup with command + R. Got os x utilities window. Opened reinstall os x and got window to setup installation of os x 10.11. Clicked continue. Asked to select the disk where I want to install os x. A recovery HD is shown and when selected I'm told the disk is locked. How do I unlock it?
Also when I open disk utility and run first aid on the HD the first aid process fails. What is the implication of the failed process?
Appreciate any help. Thanks.

Late reply. But hope it help some others. You computer symptoms suggest you should look into the cable that connect the HDD to the mother board. When that cable get damage (I don't know how) I cause those symptoms you describe there.

 

[Ledsteplin]

Late reply. But hope it help some others. You computer symptoms suggest you should look into the cable that connect the HDD to the mother board. When that cable get damage (I don't know how) I cause those symptoms you describe there.

I think my old Dell laptop has that issue.

 

[Rob Phillips]

I think my old Dell laptop has that issue.

Dude! You got a Dell!

 

[Ledsteplin]

Dude! You got a Dell!

It still has XP. LOL