Q: my unit power off suddenly and dont work again befor 2 hours later !
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May 26, 2013 8:51 AMby The hatter,TimeMachine 101
https://support.apple.com/kb/HT1427
http://www.apple.com/support/timemachineMac OS X & Mountain Lion Community
https://discussions.apple.com/community/mac_os
https://discussions.apple.com/community/mac_os/os_x_mountain_lion?view=discussio ns
Recovery Mode
http://support.apple.com/kb/HT4718
ExpressLane
https://expresslane.apple.com/
Startup Manager: How to select a startup volume
http://support.apple.com/kb/HT131
Troubleshooting: My computer won't turn on
Symptoms
If your Macintosh computer won't turn on, here's how to troubleshoot it. Please keep in mind that although your computer may display similar symptoms that prevent it from showing video, this article discusses what to do if the computer won't turn on, meaning that when you press the power button:
- You don't hear a startup chime.
- You don't hear any fan or drive noise.
- The power button or power indicator doesn't light up at all.
If your computer doesn't display any video, it may display one or more of these similar symptoms when you press the power button:
- You may hear a startup chime.
- You may hear fan or drive noise.
- You may see the power button or power indicator light up.
If any of these conditions occurs, see Troubleshooting: My computer has no video instead.
Resolution
If your computer won't turn on, try each of these steps:
- Make sure that the power cord is plugged into a working wall outlet, and that it's properly connected to the power adapter. (To check if the wall socket is working, plug in a lamp or other electrical device.)
- Make sure that the power adapter is properly connected to the power port on the side or back of the computer.
- Disconnect all accessories that are plugged into the computer, such as a printer, hub, or other mobile device.
- Reset the computer's PMU, SMC, or PRAM. Refer to the instructions for your model:
reset SMC For "Mac wont' turn on or boot" and relatedNote: It is possible that the SMC could encounter an issue that may cause unusual system behavior typically related to the symptoms described below. In some cases, resetting the SMC may be the only correct method to resolve the issue,
General purpose Mac troubleshooting guide:
Creating a temporary user to isolate user-specific problems:
Isolating an issue by using another user account
Identifying resource hogs and other tips:
Using Activity Monitor to read System Memory and determine how much RAM is being used
Starting the computer in "safe mode":
Mac OS X: What is Safe Boot, Safe Mode?
To identify potential hardware problems:
General Mac maintenance:
And a UPS suitable for your electrical wiring, but something like this:
http://www.amazon.com/CyberPower-CP1500PFCLCD-Compatible-1500VA-Tower/dp/B00429N 19W
