Looking on the bright side, the commonest manifestation of the graphics chip failure is no chime, no hard drive activity (no startup at all), and loud continuous noise from the fan. If your iBook chimes, and the chime is succeeded by harddrive activity, you may find some sign of desktop by holding the display at such an angle that you can see what is drawn on the display by bright reflected light. If so, it is probable that the CCFL backlight has died, or even, cross fingers, that the brightness control (fn + F2, then F2 alone) is at minimum. It's worth a look.

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