Please help [ibook problem]

I have a problem with my ibook g4 bought in 2005. I am just about to sell it for a good price, and the day after i receive half the money as a deposit, it decides it doesn't want to go past the blue screen in which it says 'starting osx' the blue loading bar loads fully, then it does nothing. i can move the cursor around etc but nothing else.

i have left it over night and still stuck on that screen. Also, there is a music cd in the slot so i cant put any installation disk in there. AND it just so happens my installation disk is snapped in half (mind you, i haven't looked at my installation disk in years so it could have happened ages ago)

please help, i don't know what to do and am stressing out.

I was thinking, should i just take it to a repair shop or try fixing it myself?

i just found out that there is no cd in there, i thought there was but it'd been removed.

ive tried doing command+option+shift+power all at the same time, and that did nothing, is that the same as what you are suggesting?

its quite strange becuase i didnt do anything out of the ordinary to cause this.

also, do you know what would be the going price to get something like this fixed?

Oh ok i didnt know that, thank you for your help, i shall try this when i get home for i am in sydney. btw, new 3 level apple store??? awesome.

still nothing, it won't even start in safe mode.

is it safe to say it's a goner?