problem with pc build

[jsuk1988]

I managed to build a simple pc with an MSI 865G neo2-P motherboard but i added a few new things to it ( ram graphics card and harddrive etc) and now i cant even get the thing to post. i have cleaned everything out and remounted the motherboard and tried an out of case powerup still to no sucess. The 2.88 ghz process which was in the motherboard definetly is compatible as i had a pc up and running with xp on a small hardrive. If i just use the 20 pin ATX connector and i turn the thing on the fan powers up and the cd drive i installed opens and closes but nothing else happens. when i put the 4 pin 12v atx cable in the available socket on the mtherboard, the thing wont even turn on at all. Not sure whats happened becuase i had the motherboard up and working, and it is definetly not shorting in the case as the same thing happens out of the case. I'm new to this building area and i would appreciate any advice you can give. really not sure why it wont turn on with the 4 pin cable attached now.
thanks johnny

 

[Atomic Rooster]

Are you using the separate 4 pin aux connector to plug into the motherboard or a 4 pin breakout section from the main 20/24 pin power connector?

 

[jsuk1988]

it is a completly seperate 4 pin connector. i have 2 psu's with seperate ones and i have tried both psu's and the same happens. sometimes with this connector in the fan moves a tiny tiny bit but then doesnt.

 

[nesto1000]

what are your exact specs? and how many watts are the psu's?

 

[rohan23]

You may just have a bad cable. Is your power supply modular? See if you can try using a different 4-pin cable coming from the power supply. Your power supply make be too weak to power the system. What power supplies are you using?

 

[jsuk1988]

motherboard : 865G neo2 2-p
memory : 2 ddr 266 mhz ram sticks one being 512 mb and one being 256 mb, i had it working with the 256 mb one before but have tried it in every socket now and had no luck with that.
psu: win power atx 400 . 400W supply, it had the pc working before i started adding new things.
hard drive : western digital wd2500 250gb
cd: standard 16 x cd drive which was functional before.
i had the thing working before but i added new parts to it and now im not sure, could anyone give me tips about sorting out the cmos? there are no jumpers on this board , or im just not looking hard enough. by the way when i turn this on with out the 4 pin connector the mouse and keyboard lights come on. although there is no functionality from them.
thanks all for ur help

 

[nesto1000]

hmm... i have no ideas... your psu seems to be more than enough power... sorry hope someone helps you

 

[jsuk1988]

also to mention my cpu is pentium 4 2.80ghz, apologies for not saying.

 

[rohan23]

Did you hit any parts with static while moving it over?

 

[jsuk1988]

is this something i would feel? something is definetly happening, i found the jbat1 jumper and have reset the cmos with that. when i turn it on the keyboard. cpu fan, mouse, cd drive lights up. cd drive opens n closes. and the harddrive makes some reading noise when i turn it on. but no speaker activity. realy hope i havent damaged this board.