Can you describe what you mean by it does not look right, Does it seem to be fuzzy or have less colors?
Does your machine boot and chime or does it just sit and blink?
Also what OS version are you running?
Let us know
Do you have an OS disk for the machine?
If so could you try putting the disk into the machine then press and hold the power button down until the machine shuts off, Then keep the power button held for a further 30 seconds.
Once you have done that power up the machine and as soon as you let go of the power button press and hold down the C key until the machine hopefuly boots into the setup menu, If it does just restart the mchine and see if it will boot normally
Let me know what happens.