[Solved] Motherboard or Memory ? Where's the problem ?

Hi people,

I just put together a system but i can't get it started. Here's the deal...

ASUS Mobo M4A78T-E (link)
Phenom II X4 965 B.E.
G.Skill F3-10600CL9S-2GBNT (2gbx2 DDR3 1333 mhz)(link)
Coolermaster Extreme Power Plus SMPS 600 W

So what happened was that when i booted it, it gave a single beep and then the display showed all these grids with varying colors. It then restarted on its own and then off and on.......loop

I suspected that it was the ram. So what i did was changed the slots and all that kinda stuff, but bleh =>same output.
Then i put an external graphics card some old nVidia Ge Force and then the system came to life, it started and the display was normal.
Took out the graphics card and the problem came back.

It made me think in two directions.

1) The mobo onboard ( ATI -this being 512mb shared and 128 mb side port ) GPU was at fault.

2) The mobo manual says that the DDR 3 Ram must have chips which are at least 256mb size-each. The ram that i have is 2GBx2 with each DIMM having 16 chips of 128mb each. But the RAM worked perfectly with the the external GPU in use.
Could this mean that the onboard GPU if in use must be supported by RAM which has individual chips of 256mb or more -as stated in the ASUS mobo manual ? If yes, then that means that this old nVidia GPU had a lower memory requirement and hence my ram worked with it - is it ??
So where is the problem ??? RAM or MOBO ??

Well, in any case I am getting a mobo replacement, but not sure if that is what will solve the problem ?
Could you guys please throw light on something that I maybe totally missing ?

I am really missing my machine

Thanks.
Sidd.

You said the solution...buy a GPU and all system could be work again...

If you try with a external GPU and the system works without problems, you intergrated GPU of the mobo is dead...or fail...but with the system that you have, is better that buy a GPU not integrated to the mobo..

Thanks for replying. But what about the meaning of the instructions in the ASUS mobo manual ?? It says that ddr3 ram with chips less than 256mb are not compatible.

Thanks Pinkeyes... I think the mobo replacement with do it for me !