eMac not booting

[zimmy85]

I am a high school teacher and in my lab, for the first time, I have an eMac
(1 GHz G4),that, when I turn it on, all that shows is a grey screen with an apple in the middle. I tried doing a "mac-boot" to no avail. Please help!

 

[andy.barron]

try firstly booting while holding the shift key (safe boot) & see if that lets you in.