Apple iMac G5, 20-inch - Manual (Page 259)

iMac G5, 20-inch Troubleshooting - 35 Symptom Charts
No Video
The computer will turn on, but the display has no picture or color. The boot
chime can be heard, and the fan and/or hard drive activity can be heard.
1. Refer to the iMac G5 Repair Extension Program at the beginning of the
troubleshooting chapter.
2. Check if the computer is sleeping. Press the space bar to wake the computer from
sleep mode.
3. Did the computer wake from sleep?
Yes: Put the computer to sleep from the Apple menu and wake the computer again to
test the settings. Check Energy Saver setting to see when the computer has been
designated to sleep.
No: Continue to the next step.
4. Reset your computer's PRAM (Parameter RAM).
• If your iMac is on, turn it off by pressing the power button in until the computer
powers off. You should hear the drives and fans go quiet.
• Wait for a few seconds.
• While the computer is off, with your left hand, hold down the Apple key, the option
key next to it, and the letter R. When you have them all pressed push the power
button with your right hand and then quickly move that hand to hold down the letter
P. Keep the four keys pressed while the computer starts up.
• Make sure you hold down the four keys (P-R-Command-Option) while the
computer starts up. When you keep all the keys held down, you will hear the
startup chime over and over again (about every ten seconds) until you let go. After
you hear the second chime, you can let go of the keys.
• If you didn't hear at least two startup chimes, go to step one on this page and try
again. It's important that you two startup chimes when performing this procedure.
This indicates that you have successfully reset the computer's PRAM (Parameter
RAM).
5. Does the computer display video after successfully resetting the computer's PRAM?
Yes: Problem resolved. Restart the computer from the Apple menu and make sure
the computer is starting up properly.
No: Continue to the next step.