Hangs indefinately at boot screen (Mac Quad 2.66 Xeon running Snow Leopard)

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Hangs indefinately at boot screen (Mac Quad 2.66 Xeon running Snow Leopard)

Tragedy strikes! So Yesterday I turn the beast on, and the Apple logo boot screen hangs indefinately while the loading circle spins, won't boot up.

Tried booting to the install DVD, does not see the disc when holding 'C' at boot up.

Strangely it sees the install disk when holding option, showing system drive and install dvd. However when DVD selected, spins up, hangs a bit, and then displays the grey, multi-language restart error "You need to restart your computer. Press the restart button or hold power button for several seconds to power down" (paraphrasing of course).

Attempted to flash the PRAM, didnt take the key commands or double chime, unable to flash the pram for some reason...

Some details and questions that may be relevant:

-System drive nearly full. Backed it up to the separate internal Time Machine drive i have in the tower, the night before this occurred..

System drive still has 4 or 5 gigs left though....

so thought it could be system drive not mounting, easily remedied. However the fact that the cpu wont boot from the Install DVD has made me question whether this has anything to do with the system drive at all.

-Later, right before I gave up and simply shut the system down, i suddenly heard a grinding sound. Looked inside the chassis, found one of the two small fans that sit atop the Accellero heat sinks was dislodged and sputtering about. Shut down, popped the fan back into place (these simply clip onto the heat sink via plastic clips that go between the fins). Turned on, spins as normal, no noise. Wasnt hot inside the machine and fans were spinning normally before that incident as well...

Not sure if related. If someone has had problems with the Accellero heat sink unit or its related fans and wiring, let me know what to look for and I'll take a more detailed look inside the chassis...

-Not sure if heat or power related, but place is cool in here, have multiple air conditioners. Could it be a bad switching unit in power supply? Machine turns on, stays on, but refuses to boot, maybe a single component not recieving enough juice via a minor power problem?

-thought it might be the well documented PRAM battery issue, but that usually renders blue screens at boot up. Possible?

-DID attempt to flash the PRAM at boot up, did not accept the key commands, did not doublechime, cant seem to flash PRAM

your insights are very appreciated! My music making rig is now down and im heartbroken...

Mac Pro, Mac OS X (10.6.7), Xeon quad core 2.66, 6gRAM

Posted on Jun 19, 2011 11:22 AM

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Answer 1

Best reply

The hatter

Level 9

60,980 points

Jun 19, 2011 1:13 PM in response to I Hate PCs

Run Apple Hardware Test - OEM DVD and hold down D on startup.

Pull the drives and attempt to boot from the OS X Install DVD C to insure it boots - with everything non essential disconnected.

Apple Hardware Test

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Answer 2

I Hate PCs Author

Level 1

1 points

Jun 20, 2011 9:32 AM in response to The hatter

Thanks Hatter, I will try this.

have read many posts referring to this problem where some had simple conficts with 3rd party mice and needed different drivers, to bigger problems where they had a blown logic board. Its very odd that the machine is not booting but yet it sees the system drive at option key boot. Even stranger that it sees the DVD but wont boot to it.

I will try the above steps. Also disconnected power cable while machine is off, just going by FAQs at this point...

thanks again

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Answer 3

I Hate PCs Author

Level 1

1 points

Jun 20, 2011 9:34 AM in response to I Hate PCs

btw: holding C did not cause machine to see the DVD, nor did key commands to flash the PRAM.

This is why i ended up having to hold option, whereupon saw the DVD but no boot of course.

thanx!

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Answer 4

I Hate PCs Author

Level 1

1 points

Jun 21, 2011 8:22 AM in response to The hatter

Hatter thanks for the info. last night I pulled all the drives and made sure nothing was connected but the apple keyboard but no change. Same as before, when it tries to boot to the install dvd or hardware test it displays 'restart your computer..' etc.

Think this is a blown logic board or...i have no idea, just takin shots in the dark at this point.

So upset, hoping I dont have a $2k paperweight on my hands now. Losing multimedia clients by the second.

Anyway thanks as always, you have helped me in the past and you are a credit to these boards and beyond!

-S

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Answer 5

Jun 21, 2011 8:35 AM in response to I Hate PCs

" A Mac that cannot boot to an appropriate Installer/Utilities DVD has a Hardware problem."

... and if you pulled the Hard Drives out while attempting this, they cannot be the source of the problem.

Any memory error lights on?

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Answer 6

I Hate PCs Author

Level 1

1 points

Jun 21, 2011 9:41 AM in response to Grant Bennet-Alder

Thanks Grant, where are those memory error lights and what should I check for?

These the red leds i've been reading about on the logic (mother) board?

much oblidged

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Answer 7

Jun 21, 2011 5:49 PM in response to I Hate PCs

If it hangs while starting up, remove the side door and look for LEDs right next to the memory modules. The door is not interlocked, and there are no hazardous voltages accessible to your unaided fingers (UL rules). Components may be HOT.

One other thing to try is to use Verbose mode (Command V at startup) and read the stuff that goes by. It may seem like gibberish, but sometimes it will tell you exactly what has gone wrong.

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Answer 8

I Hate PCs Author

Level 1

1 points

Jun 22, 2011 4:06 PM in response to Grant Bennet-Alder

Thanks Grant,

okay great I'll be checking those LEDs near the memory modules and will also

try booting into Verbose mode asap

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