How do you reset PRAM?

Question

How do you reset PRAM?

I have followed the instructions on Apples support doc ( http://docs.info.apple.com/article.html?artnum=2238), saying the CMD-OPT-P-R startup key combo should be pressed BEFORE the grey screen appears. Have tried this several times and Leopard just loads normally, no restart and 2 chimes.

I have also tried doing it immediately after the chime, as suggested here ( http://discussions.apple.com/thread.jspa?messageID=5587785&#5587785). No joy.

When my computer does log into Leopard though the dock and menu bar are a little slow, which makes it appear as if some caches have been cleared. Could this be a sign of PRAM being cleared?

Is there any software or terminal command that can reset the PRAM for me, coz the startup keys do not appear to work.

Thanks for your help.

20" 2.0Ghz C2D 2GB RAM Aluminium iMac, Mac OS X (10.5.1), iPod (6G) Black 80GB

Posted on Nov 18, 2007 4:39 PM

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Answer 1

Király

Level 6

10,025 points

Nov 18, 2007 4:47 PM in response to jamesfromhereford

You need to press down all four of the keys, and keep them down, until you hear the second startup bong. Then release them.

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Answer 2

Nov 18, 2007 4:49 PM in response to jamesfromhereford

You need piano lessons first. Well, not really but it is not easy to keep the four keys (option/command/p/r) pressed down and hit the power button too. And if you press the power button first and then try to get the keys down fast enough, you can easily "miss the mark" if you are just a second too late. Try getting someone to hold the p and r keys while you hold the option and command keys with one hand and press the power button with the other.

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Answer 3

Nov 18, 2007 4:51 PM in response to Király

All four keys are pressed, simultaneously, and held down. No restart appears and no more chimes are heard, Leopard just loads normally. There should still be a second chime when resetting PRAM in Leopard shouldn't there? At present i get no confirmation whether it has happened or not.

Is there no other way of resetting PRAM apart from this start up key combo?

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Answer 4

Nov 18, 2007 4:51 PM in response to David DeCristoforo

Yeh i suspected this, so have already tried. Still no joy.

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Answer 5

Nov 18, 2007 5:04 PM in response to jamesfromhereford

Or is there a way to check whether it has been reset?

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Answer 6

The hatter

Level 9

61,031 points

Nov 18, 2007 5:10 PM in response to jamesfromhereford

Do it early from a cold start to clear pram/nvram.

You could reset SMC/SMU/PMU (depends on Mac model).

Why do you want to?

I would buy Leopard Cache Cleaner. Lots of useful utilites to help maintenance and repair and to tweak OS X.

I would start with repairing your boot drive though. Using your Leo DVD or Single User Mode FSCK command.

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Answer 7

Nov 18, 2007 5:18 PM in response to The hatter

I'm having major problems with graphics on my iMac (specs are at the bottom) since upgrading from Tiger 10.4.10 to Leopard (clean install). Genie effect, spaces, dock, dashboard. All stutter are laggy and far from the smoothness of Tiger. Doing anything that involves any form of animation (not even demanding, just minimizing a window with no background apps running) will send the CPU usage of the WindowServer process through the roof. Its been discussed a lot on this thread ( http://discussions.apple.com/thread.jspa?threadID=1197125). Someone on this thread advised that resetting the PRAM has positive results, so thats what i'm attempting to do.

I use Onyx for cache cleaning and am happy with it. But thanks for the recommendation.

I have repaired permissions and the startup disk before attempting to reset the PRAM.

Any other suggestions would be greatly appreciated.

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