10.6.8 upgrade killed my iMac
I have a late 2009 27 inch iMac. Following upgrade to 10.6.8 machine worked ok at first. I went away for a few hours and when I returned could not log back in (my password was not accepted). Finally turned machine off with the on/off button, but since then, despite repeated attempts I can't reboot. Have tried holding "C" down to boot from Snow Leopard install disk and tried booting in safe mode too. No luck. In fact, I don't get starting chime at all. I was getting the Apple logo and spinning disk (forever) but having disconnected my external drive and all other usb devices now I get only a blank screen. Biggest frustration I have had in over twenty years of owning Macs. Thoughts on how to fix very welcome.