8.Press the power button. Check to see if LED # 2 comes On, comes on momentarily, or stays Off. LED # 2 is On: The Power Supply is functioning. Go on to the next step.
LED # 2 comes on momentarily or stays Off: Replace the Power Supply.
9.At this point in the Power On process, you should hear a boot chime and see that LED #1 and
#2 are On. Do you hear a boot chime?
Yes: The power systems of the computer are working correctly. See “Troubleshooting No Video” in this chapter.
No: The logic board is not passing the
Appears to be a “no power” situation, but the computer turns on, the display remains black and the fans are running.
Make sure all software updates have been applied to the computer. Refer to KBase article 303903,
Video
No Video, No Boot Chime
The computer will turn on, but there is no boot chime and no video on the display. The faint sound of the fans, hard drive, and optical drive may also be heard.
1.Make sure all software updates have been applied to the computer. Refer to KBase article
303903,
2.Follow instructions in the “General Information” chapter to reset the SMC. Does the computer display video after successfully resetting the SMC?
Yes: Problem solved.
No: Continue to next step.
3.Verify that only supported SDRAM memory has been installed and that it has been installed
correctly. Unsupported and/or defective memory can prevent the computer from booting. It may be necessary to install known good memory for testing purposes and replace any unsupported or defective
Yes: Problem solved. Verify full system functionality before return the system to the customer.
No: Replace the logic board.
iMac
