28 - iMac G5, 17-inch Troubleshooting Symptom Charts
13. Unplug the iMac G5 and remove the SDRAM. Replace with known good SDRAM.
Plug the iMac G5 back in and start the unit by pressing the two internal power pins.
Does LED #3 light now?
Yes: Replace the original SDRAM and test again. If LED #3 does not light with the
original SDRAM, replace the SDRAM.
No: Continue to next step.
14. Unplug the iMac G5 and remove the optical drive. Plug the iMac G5 back in and start
the unit up from the internal power button. Does LED #3 light now?
–Yes This indicates the optical drive has failed. Replace the optical drive.
–No Replace the logic board.
15. WIth LED #3 on, turn the machine off by holding the internal power button until the unit
powers off. Unplug the computer and reinstall the back cover. Return the computer to
the upright position. Plug in the computer again and power on the computer. Does the
computer have video now?
–Yes Restart the computer and make sure that the computer is operating properly.
–No Continue to the next step.
16. Turn the display at an angle to you and look closely at the display. Is the display
completely black or can you see a dim light or glow to the display?
–Completely black: Replace the inverter.
–DIm or light glow: Replace the LCD panel.
Scrambled or distorted video
Refer to the iMac G5 Repair Extension Program for video and power issues mentioned at
the beginning of this chapter.