Shuts off after one minute
It will not boot up completely. I have tried safe mode, apple hardware test. But get this: I removed the powersupply and checked visually and saw no burn marks. Diagnostic lights all come on. If I leave the lcd screen disconnected and connect an external monitor it boots up fine, but the fan is a lot faster, I imagine because of the temperature sensor not plugged in. What is up? I will not venture a new lcd as I have had a really bad experience on another imac in the past (brand new replacement lcd fried in 30 seconds after installing! $700 USD down the drain!). Could the mainboard be over heating but the fan going faster is compensating? Does not make sense.