This is a weird one and I haven't found any posts online with someone with this exact issue. Here's what I'm seeing:
When I turn the Imac on I hear the startup chime but get no display on the screen, after 20 seconds the fan starts running really fast/loud, then it quiets down to normal and then after about 40 seconds I get the flashing folder in the middle of the screen with a ? on the folder. Then the login screen appears and I can attempt to type in the password. I have tried booting to single user mode and from a cd but neither works, the system boots just as described above each time I turn it on, no matter what keys I press on startup.
The model is A1145. Anyone have any suggestions as to what is going on here. I'm fairly new to repairing MACs and have tried some of what looks like the basics, resetting the PRAM and SMU, which don't seem to work either (with PRAM i'm not getting a second chime to tell me it's reset).
Anyone have any insight as to what may be going on here?