Revision of iMac Mid 2007 strats up screen goes black (LED 4)
Hi All Repairmen,
Can you help me solve this issue ?
After reapplying thé CPU and GPU heatsinks, thé CPU fan runs wild, after a few seconden when after starting the iMac.
LED 4 (LCD) goes OFF after 2 minutes approximately.
I did already reset the SMC and PRAM.
Will reinstalling MacOSX on a new harddisk and original disks help ?
I will be glad hearing from you.
When I ran ASD 3S116 the GPU Proximity Sensor test gives an error TEST FAILED.
Is it possible that the heatsink assembly is broken ?
Another tought , I applied a thermal pad over the two memorychips in one peace.
Maybe this way the GPU Proximity Sensor can't generate a readout ?
When started I have video signal on the screen. After 2 minutes it goes black. The LED 4 goes OFF.
I checked the thermal sensors and they are installed correctly.
Maybe the LCD thermal sensor is disconnected or is covered with dust ?
I blew out a lot of dust under the plastic wrapping on the backside of the LCD panel.
Maybe you can help me further ?
New developments, replaced the GPU Heatsink with an other videocard ATI HD 2600 Pro:
Problem with ASD testing: GPU 0 Die Test 1
Error: Sensor reading above alarm point.
Replace the ATI HD 2600 Pro videochip ?