Computer turns on, but monitor does not..

[Reiboy]

Computer turns on, but monitor does not display, i changed the RAM and Processor but still nothing

 

[ksiemb]

Computer turns on, but monitor does not display, i changed the RAM and Processor but still nothing

No reason to change ram & Processor to fix monitor problem!
If a PC, check cable connection, remove graphics card, clean, reseat, and try the monitor on another computer to see if it functions.