No Video, No Startup Chime, 3rd LED is Off
i've got an iMac 20 inch (Late 2006) with a booting problem. After pressing the power button i can hear noises from the fan, harddrive and so on, but there is no video signal the screen stays dark and there is not the usual start up chime!
I did a little research and opened the iMac to locate the 3 service leds. When i start up the iMac only LED 1 and 2 are glowing and the white big LED on the front panel stays on. The third LED on the right hand side of the memory slots stays off.
I tried to reset the SMC according to the service manual i found here: http://www.scribd.com/doc/46053763/iMac-... on page 158, but this didn't help at all. All i got was a high spinning fan and still no video signal. After removing the power cord again, waiting, pluged it in again, powering up the high fan spinning was gone again.
At the moment i got only a wirless Keyboard, so i can't reset the PRAM. Is that right?
I removed both RAM memory bars, but still no luck. No video, no start up chime, no third LED. Not even a beep for the missing memory. The RAM memory work flawless in a old MacBook. Trying the memory of the MacBook in the iMac didn't helped too.
So, my question is: is the Logic Board or the Screen? Anything else i should try?
Thanks in advance for your help, suggestions and support.