Apple 24-inch mid 2007 Benutzerhandbuch

iMac (24-inch Mid 2007) Take Apart — Symptom Charts 

Power On Self Test (POST) Tones

Intel-based Mac computers such as the iMac (20-inch Mid 2007) rely on a combination of tones 
and blinking LEDs to display Power On Self Test (POST) error codes.

If the computer detects out-of-specification or no SDRAM or the RAM installed does not 

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meet the appropriate specifications, the screen will remain black but the computer will beep  
This error condition may be due to physically damaged RAM, installing the incorrect type of 
RAM, or not having RAM installed.
Some RAM may appear to pass the Power-On-Self-Test (POST) but still cannot be used by 

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the operating system. In this case, the computer will display a gray screen, sound three tones 
and repeat the tones until the computer is turned off. 
The solution to both of these situations is to first re-seat the memory and test the computer 

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again. If the memory fails the POST test again, try memory that has been verified to work 
correctly on another system (i.e., “known-good”) or order new memory.

iMac display is black and the system beeps nine times (3 short, 3 long, 3 short), 

then repeats

In order to recover from this error condition perform the following steps:

Disconnect the power cord from the iMac

1. 

Remove the memory access door.

2. 

Remove the glass panel.

3. 

Remove the front bezel.

4. 

Remove the small coin battery located on the logic board near the right speaker. Wait 30 

5. 

seconds.

Reinstall the battery.

6. 

Connect the power cord to the iMac.

7. 

Verify that the system powers up correctly.

8.