Mac Pro 2008 (alum tower) not booting

[Hgben]

Hi,
I’m hoping someone might help me with a recalcitrant Mac Pro.
Yesterday the visuals started flickering and rolling horizontally. After quite a few minutes I did a hard reset. Now I cannot get it to boot. The Apple logo appears but the progress bar freezes about 40% along. I usually use cordless keyboard so swapped it out for a usb one and have been unable to start in S.A.F.E. mode, get into disk utility etc with keystrokes. I have isolated pairs of RAM to see if any failed units are preventing booting as I had that once before but same pattern. I have an external bootable backup drive but Not sure how to get it to select that when I can’t get it to give me any options.
Any advice on further troubleshooting would be most appreciated.
Thankyou

 

[Harry Trent]

My first guess would be failed hard drive. What is the year of manufacture of the machine? New hard drives are really cheap these days. You can pickup a 1TB drive for under $50 off of Amazon. It doesn't have to be one manufactured by Apple. A hard drive is a hard drive. However, you would need to find a working Mac that you could use to partition and format the drive with the Apple file system. You would also need a USB cradle to be able to connect the new drive to another MAC computer in order to do the partitioning and formatting.

 

[Hgben]

My first guess would be failed hard drive. What is the year of manufacture of the machine? New hard drives are really cheap these days. You can pickup a 1TB drive for under $50 off of Amazon. It doesn't have to be one manufactured by Apple. A hard drive is a hard drive. However, you would need to find a working Mac that you could use to partition and format the drive with the Apple file system. You would also need a USB cradle to be able to connect the new drive to another MAC computer in order to do the partitioning and formatting.

Thankyou, Im working on assumption it’s the graphics card, so am awaiting new one in post.

 

[Harry Trent]

It's possible it could be a failed video card but the fact that it displays images up to the apple logo makes me thing the hard drive has corrupt data that cannot be read. If the GPU were failed I'm thinking it would not display images at all. Keep us posted.