Sigh. Mac Pro won't boot.

[ka jowct]

From any internal or external drive. I can access the recovery partitions, and have run Disk Utility, which reports no issues on any volume. Boot up appears to begin, and then stalls either at the logo and spinning indicator, which spins forever, or in Yosemite, it goes to a white screen after the progress bar has gone about a third of the way across. I have externals disconnected, and have tried numerous time to boot with just single internal drives installed. Same result every time. NVRAM resets and power resets (numerous) have accomplished nothing. The only thing I can get to is the recovery partition on one or another drive, one Mavericks and one Yosemite.

Trying to start in safe mode, but still stuck on the spinner. Any thoughts?

2010 model.

It booted up correctly when I first started today, but I wanted to check the Xprotect version on an external drive and booted from that one. At some point, I started getting a bunch of error messages about improperly installed kexts, had to power off to get out of that loop, and after that, it has not been possible to boot from any drive.

[neophyte]

PRAM reset (at least 6 chimes)? Will it boot from a DVD install disk? Just guesses on my part.

[ka jowct]

NVRAM is the new PRAM reset, same key combo. Did it about 4 times. Trying to boot from the DVD is probably my next move.

[WHiiP]

I say it just might be the :

Apple Menu (hold the 'alt' key down) select System Information.
That will list the 'model identifier' in the hardware section.
Enter that into google along with 'PRAM battery' or 'NVRAM battery' & you should find the battery type & probably the spec.
Chances are it is a coin cell…

this little battery.

[ka jowct]

The battery was replaced within the past year.

[OWC Jamie]

Despite its age what is its current voltage

[ka jowct]

Don't know its voltage, but it is the correct battery, and there wasn't actually anything wrong with the one it replaced, as it turned out. I've never had a machine that failed to boot due to a weak or dead PRAM battery, though.

I'm now getting stuck at the same spot, trying to boot from the system DVD. Apple logo, spinning wheel.

[anonymouse1]

Hail Mary time.....

Any cards installed besides video cards?

Tried booting from known good hard drive?

Tried booting from a different HD bay?

Tried going with a single RAM stick? Tried different single RAM sticks?

Wait a minute---it will boot into Recovery Mode, but not from system DVD? That's really strange. Try disconnecting DVD from motherboard? Very longshots here...

[GGD]

Since you can boot into the recovery partition, does Disk Utility see the main boot partition? Does First Aid report any problems with it?

Also, have you removed all other external devices (USB, FW, TB, etc), maybe even try removing it from the network.

One other thought, do you have an Apple Hardware Test CD that you can try running?

Also, can you boot these drives on another Mac? I'm wondering if the drives are being corrupted by the MacPro.

[ka jowct]

From the recovery partition, I ran DIsk Utility on every volume when this first started. No problems found on any of them. Everything is disconnected except the keyboard, and the connection to the KVM. The KVM is working with other attached computers.

I put in the original 1TB drive and am reinstalling Mavs on it via the recovery partiton. Will be interesting to see if that drive boots. (Time remaining about 50 minutes.)

I haven't tried the hardware test disc yet. Seems like it should have been able to boot up from the original install DVD, though, if there is nothing wrong with the hardware.

I don't mind replacing it, really, except that it has one of my Peak LE installations/licenses on it. If I move that drive to a new Mac Pro, the license becomes invalid, and it may not be possible to get another one. The Soundsoap folks have been helpful about that in the past, but I don't think I can count on that continuing.