Failure to reset Mac's PRAM and NVRAM

I wish to re-set my Mac's PRAM and NVRAM. But when I hold down Command-Option-P-R, it doesn't allow my computer to start up.
It turns on the grey screen, makes the start up noise, but then drops back out again, and it keeps on doing this in a loop.
How do I resolve this?
Can you not rest your PRAM / NVRAM if you operate on split platforms os x / win.?
Many Thanks

That's exactly how it works. See Resetting your Mac's PRAM and NVRAM.

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HT1379 Guys please help? My MacBook Pro won't start up. I have tried the resetting Mac's PRAM and NVRAM procedure with no success. All I see is just the black or grey screen although I hear the drive running.

Guys please help? My MacBook Pro won't start up. I have tried the resetting Mac's PRAM and NVRAM procedure with no success. All I see is just the black or grey screen although I hear the drive running.

Hold shift key down while booting should get you in
go through this list and get back with me
Step by Step to fix your Mac

If I reset my Mac's PRAM and NVRAM because the question mark in starting up . Will that earase anything ?

If I reset my Mac's PRAM and NVRAM because the question mark in starting up . Will that earase anything ?

Hold the option key down and boot your computer, a row of icons appears, select your OS X and click the arrow
Once in, head to System Preferences > Startup Disk and select yours, this will tell the firmware again what your supposed to boot from.
If that doesn't work, then run through this list of fixes
Step by Step to fix your Mac

Resetting your Mac's PRAM and NVRAM

I know this may seem silly but anytime I read something about "resetting" something on my imac I get nervous that I'll lose EVERYTHING lol. So is it safe to reset the PRAM and NVRAM w/o losing important files? My mybooks aren't working and this is something they suggested I try.

So is it safe to reset the PRAM and NVRAM w/o losing important files?
Yes.
(46169)

Will resetting pram and nvram on Mac osx help download problemss?

I have a new imac which I play Sims 3 on. The game plays really well but I am unable to download content from the official EA exchange website. When I try to do this by clicking on the link everything freezes and I get the spinning rainbow curser.
To troubleshoot this I have uninstalled, reinstalled and added latest patch. I have tried safari and firefox browsers.
A person from EA help said to reset the PRAM and NVRAM. I have been told how to do this, but am a bit worried as it sounds a bit extreme? The imac is only 3 days old and I don't want to break anything

Phew problem solved! Instead of using Safari I had to use Firefox. But then I had to select some boxes...I did not do that the other times!
If anyone else has that problem the answer is
Open firefox
-firefox
-preferences
-Applications
Then scroll down to Sims3 and select Use The Sims3 (default)
I have no idea what it all means but it works.

HT1379 why do i need to resetting PRAM and NVRAM

why do i need to resetting PRAM and NVRAM

why do i need to resetting PRAM and NVRAM
If you computer is working fine you do not need to reset this. It is not a maintenance procedure.
Mac OS X: What's stored in PRAM

Resetting PRAM and NVRAM

Is it ok to have a PRAM and NVRAM reset two times a week?

No, it doesn't do any good unless you're having a problem that those procedures fix.
Edit: I've never reset PRAM or SMC/NVRAM on 4 out of 5 macs.

Resetting PRAM and NVRAM bring Bluetooth back

My MBP Bluetooth menu lost somehow and could not connect to
"Apple Wireless Keyboard" and "Microsoft Bluetooth mouse",
the following steps seemed working:
1. Resetting PRAM and NVRAM:
http://support.apple.com/kb/HT1379
note you have to "Hold the keys down until the computer restarts and you hear the startup sound twice".
2. Connecting to "Apple Wireless Keyboard":
http://support.apple.com/kb/ht1809
** "First unpair the keyboard If the unpaired Mac is within 33 feet
(10 meters) of the computer your keyboard is currently paired with"**
3. Connecting to "Microsoft Bluetooth mouse"
http://www.microsoft.com/hardware/mouseandkeyboard/features/bluetoothhow_toconnect.mspx
note you have to hold the connect button on the bottom of the mouse:)

Most likely an issue with the system management controller interacting with the bluetooth host controller, it can be reset by doing 1 of these three depending on your situation:
If you have a desktop computer: Unplug it from the outlet and anything plugged into the firewire/usb ports, leave it that way for 45 seconds minimum check it again and see if it mounts in disk utility
If you have a laptop do one of these two steps and post back if it mounts:
Removable battery: Remove battery, disconnect charger(power adapter), hold down power button for 5 seconds, put back in battery should resolve
Embedded (non removable) battery: plug in the power adapter/charger, turn off computer, hold down on the LEFT side of the keyboard Shift-Control-Option. While your holding all of these press the power button once, let go of just the power button. Two seconds or so later let go of the rest of the buttons, you'll know this step was successful if it didn't turn on.

PRAM and NVRAM on intel mac

Do Intel Macs have a PRAM? I need some kind off prof like an Apple doc. There seams to be a lot of people still using optioncommandR-P to fix issues but it doesn't seem to be actually reseting PRAM. Can some one tell me the difference between PRAM and NVRAM?

There are very few instances where resetting PRAM would be used for troubleshooting OS X. Note the reference in that article to another article about what OS X stores in PRAM. Most users posting on these forums about problems they have may try troubleshooting methods that are not relevant to their problem hence their conclusion that they don't work. Furthermore, just because resetting the PRAM doesn't solve a problem doesn't mean it doesn't work, but that the problem is more serious.
PRAM can on rare occasion become corrupted as a result of a radical system crash or runaway software problem. The main effects may be loss of information on the boot volume (only truly relevant in a multi-drive system,) video settings, and date and time. More important is whether the battery that maintains the PRAM is dead or dying which can cause the loss of PRAM information. In this case resetting the PRAM will only fix the problem until the computer is shut down after which the PRAM data will again be lost. Replace that battery within 3-5 years if your machine uses one. Some laptops have separate PRAM batteries while others rely exclusively on the main battery - hence the need to keep the main battery properly charged.
Resetting PRAM and repairing permissions are probably the 'best known' things to do if you have a problem. However, neither solves very many problems and rarely solve the kind of problems users frequently post.

I reset PRAM and NVRAM and PMU screen on ibook dark can't see

Hello. My g3 ibook screen was changing from darker to okay. I read the forums about reseting pram and nvram and pmu. So, I reset the PRAM and NVRAM, scren went completely dark. It still would chime and boot up. Witha flashlight you could see desktop. So, I reset PMU, now no chime and still desktop is dark. What happened? I don't have a cable yet to hook it up to an external monitor. I ordered one on eBay, should have this week. What did I do to the ibook? More importantly what can I do to make it work again.

Does adjusting the angle of the display make a difference? (A little forward or a little back?)
Here is the link to Apple's Knowledge Base article on troubleshooting portables that won't turn on or start up:
http://docs.info.apple.com/article.html?artnum=50959
Maybe something there will help.

IMac screen is black, Resetting PRAM and NVRAM did not solve

Hi
My iMac screen just went black. I tried
Resetting PRAM and NVRAM and the SMC but it didn't help.
The computer starts up and shows the gray screen, but within a second it just turns black.
I need help please!
Thanks

You can try to reset the SMC by unplugging the power cord from the back of the iMac for 1 minute. You can also try to start up to the install DVD by holding command+C on startup with the disc in the iMac. If it does the same thing after the SMC reset and when you try to start up to the install DVD I would take it to an Apple Store or Apple Authorized Service Provider for hardware tests.

Pram and nvram

Hi. My G5 ppc has been acting very weird recently. It's been freezing. After extensive googleing, I run a memtest, then took out some ram. No change. Then I reset my pram and nvram. Seems to have soughted it out. But when I restart I get a warning that the date and time is wrong even though my g5 displays the write time and date. Should I reset pram again.
Antony

Antony Smith wrote:
Hi. My G5 ppc has been acting very weird recently. It's been freezing. After extensive googleing, I run a memtest, then took out some ram. No change. Then I reset my pram and nvram. Seems to have soughted it out. But when I restart I get a warning that the date and time is wrong even though my g5 displays the write time and date. Should I reset pram again.
Antony
Take a look at your system.log file in the Console utility. When Console comes up, you will see the console.log file. Click the "Logs" icon, then click "system.log" in the list. Find the boot area, which usually starts with a line with the message "standard timeslicing quantum is 10000 us" in it. Note the time stamps. If they are late 1969, then the clock was reset. Note also that at some point, the time stamps will change to current time.
Now, what happens to set the time is that if you are connected to the internet, the machine will automatically seek out a timeserver, usually time.apple.com, and read the current time from there. This may be delayed enough in your case or you are automatically booting into your user account and the process hasn't completed and you get the message, though by the time you look at the menu bar, time has been updated.
If you get the message after one reboot, then I would be surprised.
Bottom line to your question, though, is that I don't think a PRAM reset would solve the problem if you are getting the messages on every boot.

HT1379 I am trying to reset NV/RAM PRAM and am instructed to use the option key. I cant find an option key on my keyboard. Does it have another name?

I am trying to reset NV/RAM PRAM on Apple website and I am instructed to use the options key. There is no options key on my 2008 keyboard. Does it now have another name?

Step by Step to fix your Mac

Resetting PRAM and NVRAM Revert System to 9400m?

I just noticed this and was wondering if it was a common occurrence. If I have my MBP set to use the 9600m GT and I decide to reset the PRAM/NVRAM, will the computer automatically revert to the 9400m after such reset. I just noticed that my graphics settings changed by itself and could only draw up the PRAM/NVRAM reset as the cause. Is this the case? Thanks!

Yes it is

Cant reset PRAM and NVRAM!!!

hi i having trouble with my macbook, and i need to reset the Pram but i cant i have been trying for more than 10 times and i cant reset the pram with cmd+alt+p+r. is there any other way to reset the pram,, maybe its cause i put a password on openfirmware?, i want to the rid of the password too!!! is the anyway to get rid of the password?
i dont have any Os installed on my MAc so icant download any app

Greetings,
Read this article on the Open Firmware password: http://support.apple.com/kb/HT1352
Enabling the password disables a variety of startup keys including the PRAM.
Follow the section of the article for activating the Firmware password and in step 5 remove the check mark for "Require password...". This will disable the firmware password allowing you access to the startup key combinations listed in the article.
Cheers!

Failure to reset Mac's PRAM and NVRAM

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