Unresponsive Mac - PC not starting

[mathews]

I am MAC user. From moring onwards my computer is not starting. Its totally unresponsive. I tried unplugging the cables and all but no response.

Should i take it to repaire center or is there any way i can do it...? Please help

[SalVatore]

Lets try some troubleshooting in this case:-

1. You must be sure that any power strips are on and working. Try starting your computer from several electrical outlets.

2. Insert the the Mac OS X CD and hold the "C" key while powering on your computer to boot from the disc and not the computer's internal drive. Run Disc Utility from the CD to diagnose and attempt to repair some hardware problems. You can also erase the hard disc and reinstall OS X with this method, although you won't have a chance to back up your data.

3. Reset the power management unit by disconnecting the power cord from the back of your computer. Wait 2 minutes before reconnecting the cord and turning on your computer. Laptops and older computers have different procedures for resetting the PMU, which you can get from Apple's website

4. Press the "Caps Lock" button on the keyboard and see whether the green light comes on. If the light comes on, but your Mac won't start, the computer might be asleep and may need to have the power management unit (PMU) reset or serviced. Press and hold the power button for 5 seconds to see whether the computer will turn off or wake up.

5. Drain the logic board's battery on your Mac. Disconnect the battery (for a laptop) and the power adapter, then press the power switch and let the computer sit for about 25 minutes before reconnecting and booting it. This step forces the computer to reset its logic board and all other components that use the backup electrical charge.

6. Open your computer and remove any RAM upgrades that you've installed. See whether the computer starts up without the extra memory. Incompatible or incorrectly installed memory can make your computer unresponsive.

[Devasis]

Disconnect all accessories that are plugged into the computer, such as a printer, hub, or iPod. Reset the computer's PMU or PRAM. Try plugging a different power cord into the computer (if you have a working one available). If the computer starts up, replace the old power cord. If the computer uses a power adapter, try connecting a different power adapter to the computer (if you have a working one available). If the computer starts up, replace the old power adapter. (Computers that use a power adapter include MacBook, MacBook Pro, iBooks, PowerBooks, Power Mac G4 Cube, and Mac mini.)

You can connect your Mac to another one with a Firewire cable and then boot your computer in target disc mode by holding the "T" while turning it on. This mode can give you a chance to copy your important data from the computer while you troubleshoot it.