I have a 2010 21.5 iMac. During the boot-up I hear the chime and the fan is working but there's no display, only a black screen.
I have tried the usual fixes (reset parameters, etc) but it doesn't make a difference. I have connected to a new iMac and tried the target disk mode, however that doesn't help.
I am wondering if it could be a logic board issue?
Is there something else I can check or other troubleshooting I can do?
It could be a logic board or a GPU (those GPUs are "removable")
If you are not seeing the grey screen, try booting in Verbose Mode (it will be a text boot).
If you have another computer, trying pining the iMac. If you don't know the IP address of your router, you can find it by finding it in the DHCP settings of your router (refer to your router manual for details). If you can ping the iMac, then the chances are, it's your GPU.
If you can't ping it, then it's not booting and it's probably your logic board.
It's time to take it in for service.
