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How to Reset Parameter RAM (PRAM) - Macs

Resetting Parameter RAM (PRAM)

PRAM stores certain system and device settings in a location that Mac OS X can access quickly. Exactly which settings are stored in the computer's PRAM varies depending on the type of computer as well as the types of devices and drives connected. To reset PRAM:

1. If computer is on, turn it off by choosing Shut Down from Apple menu.

2. Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in Step 4. Note: If keyboard does not have an Option key, use Alt key instead.

3. Press power button.

4. Immediately press and hold Command-Option-P-R keys.
Important: You must press this key combination before the gray screen appears.

5.Hold down keys until computer restarts, and you hear startup chime a second time.

6.Release keys.

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mb324ll/a white screen


1.Try a Safe Boot
Mac OS X 10.2 and later Safe Boot includes disk checking and repair. First start your Mac in Safe Mode. To do this, shut down your Mac. Now Turn on your computer by pressing the power key while holding down the Shift key. When you see the Apple logo, release the Shift key. After your Mac fully starts, restart your computer normally without holding any keys/buttons during startup. Note that Safe Boot is slower to boot.
2.Run Disk Utility
Turn your Mac off by holding down the power button for a few seconds. Turn on your Mac and hold down the Command and R keys until you see the Apple logo. Then you should see a "Mac OS X Utilities" window. Select Disk Utility, click your OS X hard drive and select verify/repair disk.
3.Reset PRAM
This may fix your boot failure. PRAM ("parameter random-access memory") stores some of your settings. You may reset PRAM. To do that, turn off your Mac. Now turn on your Mac. Then, immediately, hold down the Option-Command-P-R keys until your Mac restarts. When your Mac is starting up, release the keys.
4.Reinstall Mac OS X
If nothing above works, you may try this. Your Mac needs to be connected to the Internet. See number#2 above. Follow the same steps. Restart your Mac and hold down the Command key and the R key until the Apple icon appears; when you see the Mac OS X utilities window, select the Reinstall option.

Mar 13, 2014 | Apple iMac A1224 20" Core2Duo 2.66GHz 2GB...

1 Answer

macbook pro dark screen


Close the lid, attach an external monitor, reopen lid.
Your display should now show on that monitr. If it is, your display on the MacBook Pro may be bad. I would try resetting the PRAM and the SMC before going to an Apple store. The SMC controls the MacBook's power founcts (see below)

Resetting the PRAM may do the trick:
You reset the PRAM by rebooting a Mac and then immediately hold down the Command+Option+P+R keys, you will then hear the Mac reboot sound again, signifying your PRAM has been reset. You must hit the key combination before the grey screen appears otherwise it won't work.

you've tried rebooting, you've reset the PRAM, you've done it all, but your Mac is still behaving strangely. What next? In certain circumstances, resetting your Mac's System Management Controller (SMC) can be a solution. This is sometimes necessary to restore normal lower level system functionality to your Mac.

Here's how to reset the SMC on any type of Mac (and any version of OS X) and the type of problems that it may resolve.
When & Why Reset SMC on a Mac? Some Common Hardware Reasons

Typically it's power and hardware related issues that can be helped or resolved by resetting a Mac SMC, particularly if you're having these types of problems:

* Issues with your Mac's cooling fans and fan management: fans run constantly at high speed, fans run high despite low CPU usage and adequate ventilation, fans not working at all, etc

* Power management and battery problems: Mac isn't turning on, sleep isn't working, random shutdowns and reboots, battery isn't charging, Mac won't wake from sleep etc

* Light problems and improper lighting management: battery indicator lights aren't working, display backlighting isn't adjusting to ambient light changes, keyboard backlights not working, etc

* Video and external displays not working: display brightness functionality not working properly, target video mode isn't working properly, external display isn't working, etc

* General performance and functionality problems: abnormally sluggish behavior despite no CPU or disk usage, external ports not working, airport & bluetooth aren't showing up, external devices are not being found, etc

So now that you've concluded you need to reset your SMC (Note that the SMC is on Intel Mac's only), here's how to do it on MacBook's, MacBook Pro's, iMac's, Mac Mini's, and Mac Pro's. Notice that the reset instructions are different for MacBook and MacBook Pro's if you have an internal or detachable battery.
Reset SMC of a MacBook Air, MacBook Pro Retina, or MacBook Pro's with an internal non-removable battery

This is how to reset SMC on most modern Mac laptops:

Shutdown your MacBook Air / MacBook Pro
Connect the power adapter to your Mac
On the MacBook/Pro's keyboard, hold down the Shift+Control+Option keys and the Power button at the same time
Release all keys and the power button at the same time
Boot your Mac as usual

Here's the key sequence to hold down:

Reset the SMC of a MacBook Air or Retina MacBook Pro

Do keep in mind that by resetting the SMC you will lose power specific settings, like the time it takes to sleep a Mac and other customizations to power settings. No big deal, but if you have made many changes to your hardware behavior you will want to adjust stuff like sleep behavior again.
Reset SMC of an iMac, Mac Pro, Mac Mini

Resetting SMC is different for non-portable Macs:

Shut down your Mac
Disconnect the power cord
Press and hold the Mac's power button for 5 seconds
Release the button
Reattach the power cables and boot the Mac as usual

Reset the SMC of a MacBook or MacBook Pro's with detachable batteries

mac reset the smc Older MacBook laptops with a removable battery can reset SMC with the following approach:

Shutdown the MacBook/Pro and remove the battery
Disconnect the power adapter, hold the Power Key for 10 seconds
Release the power key and reconnect your battery and power adapter
Turn your Mac on
Let boot as usual

Hopefully that will clear up your problems, if not it might be worth a visit to the Apple Store or a certified repair center.

Happy New Year,
Kerry

Jan 12, 2014 | Apple Computers & Internet

1 Answer

My iMac G5 computer starts up and then gets to the apple logo ,it ses like it loading up but nothing is happening.


The PRAM is the first thing to try and then there might be an internal reset button next tot he installed RAM. Seen it in older eMac and iMac desktops but not sure about yours.

Resetting the Parameter RAM

One easy fix for many issues is to simply reset the PRAM to its default state. This will cause some data to be lost, specifically the date, the time, and the startup volume selection. Luckily, you can easily correct these settings using your Mac's System Preferences.
  1. Shut down your Mac.
  2. Turn your Mac back on.
  3. Immediately press and hold the following keys: command+option+P+R. That's four keys: the command key, the option key, the letter P, and the letter R. You must press and hold these four keys before you see the gray screen during the startup process.
  4. Continue to hold down the four keys. This is a long process, during which your Mac will restart on its own.
  5. Finally, when you hear the second startup chime, you can release the keys.
  6. Your Mac will finish the startup process.

Jun 06, 2012 | Apple Computers & Internet

1 Answer

my screen is on but just have a small camera in the middle of the screen blinking.. G4 power book can you help?


I seen a blinking folder with a question mark in the middle in folder, in the middle of a display screen, but not a camera.

Either way, you are not able to access your main desktop so that is where I want to help.

A blinking folder with a ? in middle, is an indication that your bootable Mac OS X volume cannot be found.

If you do, I would first recommend you try this procedure first:
(PRAM Reset)
Normal 0 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} • First, hold in your power button for approximately 10 seconds to do a hard shutdown, if you have not already turned your Mac off.

• Once your Mac is shutdown, you will need to perform what is called a PRAM reset (Parameter RAM)
• Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously .

• Turn on the computer.
• Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
• Now, hold the keys down until the computer restarts and you hear the start up sound for the third time.
• Release the keys and allow the Powerbook G4 to start up.
------------------------------------------------------------------------------
If this still returns you to a blinking ? folder, try this process:
Normal 0 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} DISK UTILITYYou can use your Mac OS X install disc to repair your hard drive and Mac OS X volume using Disk Utility. Click the link below to try this procedure.
* Apple Support Link:
Use Disk Utility to Repair Disk

Should neither of these processes work and you still boot up to a flashing ? folder, then your only recourse is to use your Mac OS X installation disc and perform an Archive and Install procedure.
----------------------------------------------------------------------------

Normal 0 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} This procedure also allows you to save your applications, files and folders without the old directory interferring with you then accessing those files and creating a new Mac OS X Directory.

Here is the Apple Support Link for that procedure:
Archive and Install



This should get your Powerbook G4 back to normally functionality without any serious data loss.



Regards,


-Mactechtrainer

Feb 02, 2010 | Apple 15" PowerBook G4 Aluminum 1.67 GHz...

2 Answers

when turning on my macbook pro


Please clean-up the RAM modules wiping it with a dry cloth and re-insert it back into its slot .

May 06, 2008 | Apple MacBook Pro Laptop Computer with...

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