Removing BIOS battery for one min then replace may work.
Make sure CD/DVD is not on same IDE lead as HDD.
Make sure all connections inside PC are correct.
There should be a small 2 wired connection theres ome were it should be connnected on the MB,Make sure it is connected to right slot as there can usaly be a few of the same size connectors for this thin 2 cabled lead.

Please check all your connections and CPU are all seated correctly and in the right places.There does seem as if something is not connected right.

Flash the BIOS by removing battery for 1 min

i know the cd player is on its own power cord. the hdd and floppy and graphics card was all connected together along with the side fan. thats all the power cables i have though.

I ment realy as IDE cables,one cable for floppy.

Next cable only for CD/DVD drives.

3rd cable for HDDs only.

Have you tried the removal of BIOS battery?

oh ok thats fine. yea they are all on seperate ide cables. did not touch them. im at work at the moment but i will try everything later. just want to get as much possible things to try as i can because i will have to go back and try these until the morning when i can come on and give an outcome or an update and get maybe some more information. just i tried quite a few cables but did not try clearing the cmos or reseating the cpu. just gave up asthe graphics card seemed to have given in and could not get the system to run at all.

See this link:http://i239.photobucket.com/albums/f...h/P1180115.jpg not exactly that connector just one similar can be plugged in the wrong port,make sure it is in correct one.

Make sure the correct sockets are plugged into correct ports?

Like this:

Does your mobo require an extra four pin molex connector to power the cpu?

Does your graphics card require the same? the monitor/onboard/PCI four pin molex maybe connected to wrong port?

How To Build A PC Motherboards.org

ok i tried the following last night:

checked all connectors for hdd, cd player, floppy and tried every possible combination available to me.
cleared the cmos about a thousand times.
tried each memory (old and new) in each slot with every single combination after clearing the cmos each time.
replaced the cpu and heat sink and fan
tried with and without graphics card,
with and without sound card
and this is the outcome.

the graphics card fan is now powering on but still nothing on screen.
there is a light on the motherboard an amber one which stays on constantly?
the keyboard lights flash on for 1/2 a second when i plug the power cable in but does not light up again once turned on.

everything has power going to it and works as i think should (ie the hdd is powering up and making usual noises, floppy drive light comes on and stays on, cd player turns on and opens up and reads a cd when placed in.

any help from here on would be great but as far as i can see all hardware is working including the motherboard but i cannot tell if both parts of ram or the processor are working

You should not of cleared cmos soooo many times you proberly need a BIOS update now.

In BIOS did you choose PCI or AGP?

How old is this P4 what model is it?

What RAM did you buy?DDR2?SDDR?Etc?

If this is an older P4 it proberly is not compatable for DDR2.

Have you got OS disk?Have you tried booting from the disk?

Amber light on MB,are you getting any beep codes from the pc?