No power no video no sleep light no fan movement no hard drive spin no Caps Lock LED when pressed and no display illumination
Note: After each step, check that the system is not supplying power to the logic board. If you see the sleep LED come on or the Caps Lock LED illuminate when the key is pressed, then the system is indeed drawing power. In this case, hold down the power button for six seconds to ensure the system is shut down before working on the computer. At this point, the issue is no longer a 'No Power, No Video' problem. Move on to the "Power, but No Video" troubleshooting section.
Note: Examine the display carefully. An image may be barely present on the screen, but with no backlight clearly illuminating the image. In this case, the system is working properly except for the backlight. Use the "No display or dim display" symptom to resolve this issue.
- Remove any connected peripherals.
- Check that the battery has enough charge to start the computer by pressing the button next to the LEDs on the battery (on the bottom of the machine). At least one LED must light continuously (not flashing). Make sure the battery is fully seated.
- Connect a known-good Apple 60W MagSafe Power Adapter and power cord to a known-good power outlet. If the cord is properly inserted, the LED should light up; if not, go to the "MagSafe power adapter" symptom.
- Check for damaged pins or magnetic debris on MagSafe power adapter. If pins are okay, reseat power adapter connector and make sure it is fully inserted. Refer to Knowledge Base articles 303566 "MacBook Pro: Troubleshooting MagSafe power adapters with stuck pins" and 302461 "Portable Computers: Troubleshooting power adapters."
- Try powering up without the battery installed. If it starts up, try a known-good battery. If it does not boot, replace the battery connector cable.
- Press Caps Lock key to see if light on key comes on. If it does, hold power button down for six seconds to shut down the computer and restart.
- Reset PRAM. Restart the computer, then hold down the Option-Command-P-R keys until you hear the startup sound at least one additional time after the initial startup sound.
- Reset the SMC. See Knowledge Base article 303319, "Resetting MacBook and MacBook Pro System Management Controller (SMC)'; Resetting the SMC means you will also need to reset the date and time (using the Date & Time pane of System Preferences).
Warning: Make sure you do not hold down the "fn" key when resetting the SMC.
- Try to power up the system and check the sleep indicator. If the LED lights up solidly and turns off, the logic board is getting power and completing the boot cycle. Go to the "Power, but No Video" troubleshooting section.
- Verify that the power button cable is connected properly to the top case flex cable assembly and that the flex cable is connected correctly to the logic board. Try turning on the system.
- Disconnect the top case. Inspect the connectors. With the top case removed, restart the system using the on-board startup jumper pads, as shown below. If it starts up, replace the top case.
Caution: Use a jeweler's flat-blade screwdriver that is just wide enough to short the two small solder pins (jumper pads) located directly below the power symbol.
- Test each RAM slot individually with known-good RAM. (The computer should still start with only one known-good DIMM.)
- Try removing the AirPort Extreme card from its socket and start the computer. If it starts, shut it down and check the flex cable connector and the connector on the logic board and replace the damaged parts.
- Reseat these cables:
- Hard drive flex cable (will start up to flashing folder if not connected or corrupt)
- Optical drive flex cable
- Trackpad flex cable
- LVDS cable
- Battery connector with sleep switch cable
- If computer starts on battery power only, replace MagSafe board with a known-good MagSafe DC-in board.
- If computer starts up, inspect any suspect flex cable connectors and their terminals on the logic board for damage and replace any damaged parts.
- Replace logic board.
Was this article helpful?
What is So Great About Apples Design Concepts? There is always a reason why consumers are drawn to a particular brand of product. Apple has the record for drawing people in, and not just Americans, why? Ease of use, thats why.
Get My Free Ebook