How to Zap PRAM on a MAC
Your iMac's PRAM is short for parameter random access memory, and it's a piece of RAM that's responsible for keeping track of your time zone settings, DVD region settings and several other automatic settings. PRAM is a background utility that your iMac accesses every time you power on your machine. It keeps track of your settings and preferences for your display, sounds, mouse connectivity, installed memory, CD/DVD drives and any other connected peripherals. If you want to reset these connections to a default state, you'll need to reset or “zap” the PRAM in your Mac. You may occasionally experience start-up problems or kernel panic due to the PRAM becoming scrambled. Resetting it to its factory defaults will normally provide a solution.
<strong>Zapping the PRAM</strong>
You'll first need to shut down your Mac entirely and give it a minute or two for all the processes to stop running. Then turn it back on and hold down the “P,” “R,” “Option,” and “Command” keys at the same time. You should hear two chimes as the system resets itself. Be sure not to release any of these keys until the iMac's grey start-up screen appears as normal. Once your mac finishes powering back on, your PRAM settings and preferences should be restored to the factory default settings. If you're using a bluetooth keyboard or mouse, you may also need to reset the settings for these to connect to your system again.
<strong>Checking the Reset PRAM</strong>
Once you've reset your Mac's PRAM, it's a good idea to check the speaker volume settings, time zone settings and start-up sounds under your Mac's system preferences. If they don't automatically reset, you can do these tasks manually. Keep in mind that the Mac OS X system doesn't store network settings in PRAM, so zapping the PRAM is not likely to fix existing problems in this area. Zapping the PRAM is one of the most common Mac troubleshooting techniques, and it works on both Intel-based and Power PC Mac systems. PRAM rests should also work on all contemporary releases of the Macbook, including the G3, G4 and G5.
