Installation stuck at grey boot screen on Macbook Pro 4,1 (Early 2008) I would appreciate any help you guys can give me since I would really like to upgrade my laptop to Mountain Lion.

Computer: Macbook Pro 17" 4,1 (Early 2008)
RAM: 4 GB RAM
Hard drive: 128 SSD Hard drive
Video card: NVIDIA GeForce 8600M GT
Current OS: Snow Leopard 10.6.8

Steps I have taken but failed to properly install the OS.


Dowloaded Mountain Lion at least 3 times from the App store to make sure the download wasn't corrupted.
I even tried making a Lion Bootdisk so I can install Mountain Lion on a USB drive (Install ESD.dmg).
I have even tried installing Lion first thinking I would take it one version at a time but gets stuck on boot screen too.
I even changed my hard drive to a new blank SSD drive to see any difference.
Each time I install Mountain Lion or Lion, everything is good until the installer has to restart the laptop.
Laptop gets stuck at the grey boot screen with the Apple logo and the loading circle. Nothing ever happens after.
Even waited for 7 hours but no changes in the boot screen.
I always had to use/boot to the Snow Leopard CD so I can restart the laptop back to the Snow Leopard drive.


Safeboot gives me this endless message "ERROR: Firewire (OHCI) TI ID 8025 built-in: handleUnrecoverableErrorInt" but I don't have any Firewire cable connected at all.

What can I do next?
I'd do a quick triage to boot the Mac into single user mode to see if the boot drive / base OS is minimally functional. After that, I'd start with systematically working through the startup troubleshooting guide from Apple.


OS X: Gray screen appears during startup  - http://support.apple.com/kb/TS2570


You've clearly done many of the steps, but the order of steps is very helpful in knowing what the likely cause of the problem is. I might skip removing the SSD if you don't have a HDD - but installing a clean OS onto an external HD at that point might be a good way to rule in or out your SSD as contributing to the failure to install and boot properly.