iMac 2010 Won't load OS; no safe mode; repeated installs [log inside]

[Sekwel]

I'm attempting to get an iMac working for a friend. It's currently standing here open with the screen attached. Long story short, it will not load an operating system. I've installed El Capitan on it several times from recovery. The installation process seems to go fine, but I cannot boot up after that.

If I attempt safe mode, it loads for a bit, the screen flashes like it's going to take me to the desktop, and then the bar progresses a bit more before the whole system restarts.

I had originally suspected the hard drive was an issue, but now I am not certain. The drive's handled multiple OS installs (including Windows, once) without much of a complaint. I'm not beginning to suspect the graphics -- which I assume to be integrated, but I'm not sure. First time messing with apple hardware.

I've included a copy of what I could see of the verbose boot log before it completely froze on me. Any input would be appreciated. At this point I'm not sure I could fix it without replacing parts, but I wanted to see what the Internet thought, first.

http://pastebin.com/SqXdFz2L

 

[Cory Cooper]

Hello and welcome.

The issue could be several things - hard drive, logic board, RAM, etc. It is hard to determine without seeing the iMac. Strange that it will allow you to boot to the Recovery Partition and install El Capitan, but then not startup.

-Can you confirm that it will startup from the Recovery Partition?
-Do you have an external drive that will successfully startup the iMac?

If it boots into the Recovery Partition normally, my guess would be a bad hard drive.

C

 

[honestone]

Hello and welcome.

If it boots into the Recovery Partition normally, my guess would be a bad hard drive.

C

I have always wondered about that, as the Recovery Partition is created on the internal hard drive. I guess it's possible, but if the entire hard drive is bad, then how could one boot to the Recovery HD partition? Is it possible that just the partition where one wants to install the OS is bad?