Thanks Kate. I actually did something similar, after removing the battery I started it up in safe mode/ holding down the shift key down while pressing the power button. That worked quite nicely several times. I took it to Apple Store today, it is beyond repair since it is too old/ not supported any longer. (2006)
Connecting it via fire wire to the iMac and starting it up by pressing T and power button, I should be able to see the hard drive on the IMac with all the files, if I ever need to look. The computer starts up, I just can't use the screen, since it stays black.