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15 inch "Desk Lamp" iMac G4 700MHz M6498 PowerMac 4,2

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black screen after cleaning

I disassembled and cleaned the dust from a WORKING G4 iMac 700 Mhz with 15" monitor. Now I get a black screen on startup. After the startup chime a pure tone sounds three times. Then the monitor light blinks a repeating pattern: once long, 3 times medium and 1 brief flash.

I re-opened up the case and found no loose connections. This is not a backlight problem.

The tones and flashes must mean something. Anybody?

Answered! View the answer I have this problem too

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The three tones are a RAM problem. Reseat your RAM.

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BTW - did you replace the thermal paste? If not, do so.


Got it!

Thanks for the reminder on thermal paste.


I take it the RAM solved your problem?


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Steve Parmenter will be eternally grateful.
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