Mac Pro Will Not Boot

I am working on a Mac Pro A1186 Quad Core that will not boot up to the OS. The computer will power on and I hear the start up chime, but nothing shows on the screen. I can hear the fans spinning and hard drive making noise, but still nothing displays. I checked the Caps Lock button light and it will not illuminate and when you press the power button on the desktop just once for a second the whole machine shuts off. I have reset the PRAM and this has not made a difference. It was working last night and the computer was not shutdown but did go into sleep mode and now this is happening. Any ideas? Thanks.

flipside82 said:

I am working on a Mac Pro A1186 Quad Core that will not boot up to the OS. Any ideas? Thanks.

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Try an SMC Reset:

Intel-based Macs: Resetting the System Management Controller (SMC)

If this doesn't help. Double check the cable to HD connection. If this is good...it's very possible that the HD is dead or dying. It eventually happens to all HD's.

Also be sure that the boot HD is not full. You may need to boot the computer from an OS DVD, 2nd internal HD, external HD, or a bootable USB stick.

- Nick

Also if all Nick suggests fails, open her up and remove the graphics card, clean the contacts, and reseat firmly and connect. Mac Pro 1.1 used the nVidia 7300GT graphics card and they are liable to failure.

Thanks for help guys. I removed the video card and reseated with no luck. The video card has already been replaced once from the original. I also tested out a totally different video card with the same result. I removed the HD and the video card and still had the same result. I removed one RAM board and same result. I removed both RAM boards and the power led just flashed. I did the diagnostic LED's and only got the Trickle Power LED and Good Power LED. That's it. Could this be a power supply? I don't have a spare power supply to test. Any thoughts? Thanks.

flipside82 said:

Thanks for help guys. I removed the video card and reseated with no luck. The video card has already been replaced once from the original. I also tested out a totally different video card with the same result. I removed the HD and the video card and still had the same result. I removed one RAM board and same result. I removed both RAM boards and the power led just flashed. I did the diagnostic LED's and only got the Trickle Power LED and Good Power LED. That's it. Could this be a power supply? I don't have a spare power supply to test. Any thoughts? Thanks.

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You tried a bunch of things which is great…but you didn't try booting the computer from another device as I suggested above.

- Nick

When I try to boot to another device (CD/DVD or USB device) it does the same thing. Power light LED, start up chime, but nothing else. When I try to boot to CD, it does attempt to try to load the CD and you can hear it spinning, but nothing happens. So, I'm quite stuck at this point.

flipside82 said:

When I try to boot to another device (CD/DVD or USB device) it does the same thing. Power light LED, start up chime, but nothing else. When I try to boot to CD, it does attempt to try to load the CD and you can hear it spinning, but nothing happens. So, I'm quite stuck at this point.

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Ok…thanks for the update…good to know.

After rereading everything…it sounds to me like the video card may be faulty.

It's probably not the power supply. Since the computer starts up, HD spins, optical drive spins with a disk in it. When you press the power button (after it starts up)…and then the computer shuts down…that's what it's supposed to do (no problem there).

If it were me…my next step would be to try another (known working) video card.

- Nick

p.s. This is also assuming that the display and display cable are working properly.

I'm still working on this Mac Pro and eventually did discover the HDD was going bad. Looks like the motor in the drive was failing. I was able to get it to spin up long enough to copy all files and folders off. The problem is I still can't get this thing to boot up now. I put a brand new hard drive in and it does the same thing. I don't have a spare video card to test with but shouldn't it boot up without one? What's happening is when I turn it on and hear the chime its like the machine just stops at that point. The hard drive is spinning but no activity. When I press the power button to turn it off, I don't have to hold it down for 10 sec or anything it just shuts off when I press it once. If I unplug the power an let it sit for a while, and then plug it back in, it automatically powers on without touching the power button. There is still something funny going on with this machine. Any other ideas? Thanks.

Well it should boot with the video card removed, BUT not with it in place.