my pc can turn on but no display

[aeman94]

previously my pc can turn on and run a bios but after i bought a new tower,its only turned on but no display.HELP MEEEE

my pc spec is :

mobo = gigabyte ga ma770t-us3
graphic card = Gigabyte HD 5670 1GB ddr5 128 bit
processor = amd athlon II
ram = no specific details

 

[RossTheGuy]

Did you check if it's your ram?
Do you have 1-4 ram sticks?

 

[aeman94]

Did you check if it's your ram?
Do you have 1-4 ram sticks?

yes i have,but i didn't put all my ram in ram slots. last night i tried each slot with 1 stick ram.

 

[aeman94]

help me please:- (