iMac's screen stays black after I've turned on the computer

I am having pretty much same thing with my 24 inch mac, I have done everything you have said to do,I get no chimes, beeps at all ... then it will boot up just fine, and with in a few minutes it goes black...

any more suggestions...

I have a Late 2006 iMac 20in that has just gone black and won't come back. I get the chime and I see the glow but the monitor just stays black. I tried zapping the PRAM and discharging. I called around and it appears a replacement monitor is $600 plus min $100/hr service fee. I know the drive and system are functioning because I hear the spin up when I log in and I see network activity on the router. I know my machine is much older but I think we are having similar issues. If I were you I would take it back to apple because you are still very much under warranty. Unfortunately I am not and it appears I will be buying a new iMac.

I too have an 27" iMac i5.

Very often I turn on the iMac - The screen stays off, but the iMac is on, cause the hdd is working and the external drive is also on.

I have to force shutdown and then turn it on again. The iMac then turns on perfectly fine. I have reset the PRAM and the SMC loads of times, and it always helps for a little while (about 3 boot ups). But then the problem's back.

Please help me Apple. This is s...

first, try resetting the SMC:

Shut down the computer.
Unplug the computer's power cord.
Press and hold the power button for 5 seconds.
Release the power button.
Attach the computers power cable.
Press the power button to turn on the computer.

Next, zap the PRAM when you restart: Hold Command Option P R at startup.

Count me in as someone who is experiencing this same problem, only mine has yet to come on.

Welcome to the Apple Discussions!

Do you hear the startup chime on the occasions that the screen remains black? If you do not hear the startup chime each time you (re)start your Mac, there may be an issue with the RAM.

Dah•veed

David.Austin.Allen wrote:
Do you hear the startup chime on the occasions that the screen remains black? If you do not hear the startup chime each time you (re)start your Mac, there may be an issue with the RAM.

have you done any ram upgrades? bad ram should make it beep 3 times. incompatible ram beeps twice, & missing ram is one solid beep. you can try pulling & reinstalling the ram one simm at a time, but the above description is more a sign of a failing logic board, power supply, or a combination of the two.

bestofboth, could you please state the exact model of iMac with which you are having issues? Go to Apps>Utilties>System Profiler>Hardware and state the model identifier listed.

The white iMacs have a power indicator LED on the front and usually use a combination of tones and LED blinks to indicate errors. If these iMacs do not encounter usable RAM on startup the display remains black and the LED blinks three times. If RAM passes the Power On Self Test but is still unusable the display is gray, three tones sound and the LED blinks three times. The LED continues to blink three times with a pause between until powered off.

The aluminum iMacs do not have a power LED. If the POST encounters no RAM, the display remains black and one tone sounds every five seconds until the iMac is powered down. If the RAM encountered is unusable the iMac sounds three tones followed a five second pause, which is then repeated until power down.

Dah•veed

Are you using anything that would mute the startup chime, such as the Startup Sound preference pane?

I would open the RAM access on the bottom of the display and double check the all of the RAM modules are seated properly and securely in their slots.

Dah•veed

This has been happening to me too. I have a 27in quad core imac (iMac11,1). I know that the computer is coming on because my external hard drives power up, but the screen stays black.

I did what someone suggested and turned the power off, unplugged the cord, and held the power button down for 5 seconds. After I plugged the cord back in, the screen came on the next time I turned the computer on. This has been going on for a couple of months. If the solution I mentioned above doesn't permanently fix the problem, I will get back on here in a few weeks to let you know.

I have the same problem now. Someone HELP US!!!

Forgot to mention I have a 27" iMac i5.