Have your tech check for swollen electrolytic capacitors. Usually by now all the units have failed that had this issue but there will be more.
Hardware: iMac, early 2008, 20" aluminum, 2x2 G ram, 10.6.8
On startup the computer "boings", makes some regular startup crunching then goes silent: the question mark folder appears.
I can get the computer to boot and connect to the HD by using this exact technique:
Unplug both ends of the power cord for half hour.
Insert power cord in back of the imac only.
Hold down power button for thirty seconds.
Let go, and wait for 25 seconds.
Plug cord into power outlet and push start button.
This time the power button will have to be pushed two or three times. Computer then boot perfectly!
Additionally, I have run diagnotics and HD appears okay, permissions seem to keep going bad, especially java, but I've heard that is normal.
Thanks for any help from experienced users and pros!