So basically I can't boot from my ssd anymore. It just shows a grey screen with an error symbol. I can't get into target disk mode and none of the other boot shortcuts seem to be working either. When I have my old OSX HDD in there and the SSD attached via USB however I can select the SSD from the boot menu and boot it just fine.
Also, booting from the HDD works just fine. I was under the impression that the boot menu wasn't tied to a disk but supplied by efi or whatever. But given the current behavior that doesn't seem to be the case?!
Any ideas what my cause this and solutions are greatly appreciated!
UPDATE: I wiped the SSD and used carbon copy cloner to clone my working HDD onto it, but it still won't get anything besides a blank grey screen with the occasional failure sign...