I have a IIci with the same symptoms - power supply clicks, fan lurches, while the power button is pressed.

I hooked a meter to pin 10, and it's steady at 5v. I jumpered 9 to 10 to get it to start up, and it does the click, lurch thing.

If I work out a fix, I'll post it here. I'm going to dig in and see about leaky caps.

In the meantime - does anyone know where I could get a replacement, in case I foul it up worse than it already is?