My computer monitor doesn't come on when i turn my computer on

[g4mer]

Hi,
i pluged in my hard disk to another computer to format it. Now when i was finished i pluged my hard disk back to my pc. Now when i turn on computer monitor just go to sleep and nothing happends. I dont have any OS right now and i cant modify anything. Maybe i did something with my hard disk wrong i dont know. please help me.

 

[strategic]

Why did you take it to a different computer to format?
Do you have the o/s cd in the drive to boot from?

 

[g4mer]

I take it to different pc because i had 3 partitions that linux created and i dont know how to merge them. I tried to unplug everything and plug it back and now works fine. Maybe i accidentally dislocated something till i was unpluging my hard disk.