Monitor not displaying any signal

[mrboots123]

i have recently built a new computer from scratch but when i try plugging in the monitor i receive a no signal coming from it all i see is the light light up for a second then goes back to amber. the computer seems to run fine when turned on all the fans start spinning it just wont display anything on the monitor. i have tried resetting the cmos, removing the cmos battery, unplugging and replugging everything.
the computer spec are
motherboard:GIGABYTE GA-A55m-DS2
Ram: Patriot 2gb
cpu: amd a4-3400 series
psu: antec 450w

 

[sormon]

- You know if that monitor is functional? If you don't know for sure another monitor will also help for testing.
- Is your case having a speaker? If not, you may need to buy a system speaker, that will help you to find out the POST error message.
These are two things that came in my mind now.

 

[mrboots123]

i have tried 3 diffrent monitors alll which are functional but none seem to work also the computer has no case speaker