Why wont my screen start up after i build my computer

[Apokalipse]

yes that is a possibility; The BIOS is supposed to give beep signals when there is an error. A lot of the time it is the only way of telling you there is, if like in this case, the video is not working

 

[Cappy]

Its allways a good idea to study up on How to build a Computer

 

[zilantyas]

Also be sure you have a good monitor. If possible hook your monitor up to another PC to test it!
Are you getting any lights on the monitor?
Thermal grease is a good idea....it couldn't hurt!