Hi everyone,
 
I really hope someone can help me with this.  First off here are my system specs:
 
ASUS P5N-E Motherboard
MSI NX8800GT
2x Kingston 2gb RAM
2x SATA Hard Drives
Intel E6850 CPU
DVD writer
Antec EA 500-EC EarthWatts 500W
 
I just put the system together on Sunday. It worked pretty OK, I installed XP fine and everything was OK. The next morning I turn it on and all the fans come on (graphics card, CPU, case fan), all the lights and so on, but there's no signal to the monitor. I tried unplugging etc but no change.  
 
 Now I'm a complete newbie at this, this is the first build I've done and I was so chuffed, until this. I really want to get this up and running so if anyone has any suggestions I'd appreciate it. I searched the forums here but couldn't find anything, but feel free to point me in the direction if I missed it.
 
Thanks in advance
 
ruisleipa

Make sure the video power cable is plugged right and try to reinstall the memory sticks and main and aux(4 pin) connector. For now unplug any printers card readers and other usb devices you are not using,

Do you have a pc speaker plugged? if should beep out error codes to help tell you whats wrong.

When all failles disconnect anything you do not need and maybe even run the board outside the case on the anti static bag(and near the edge of a table/desk so the expansion cards fit right) it came into to rule out a short from a misplaced motherboard stand off(those little brass things the board screws into). If that does not work and you have(or have access to) an old pci video card, try this as well in case you are unlucky enough to have a video card that just died.

Try to change RAM sticks. Put them in the black slots.
Earllier BIOS versions of this MBO were a little bit picky, and greater stability was achieved by putting the RAM into black slots.

As nukemaster said, maybe some cord got unpluged during the night (by a little computer fairy ) so check all the connections.

Hope this helps.

Try re-instaling your vidio card. Its possible that it was not in the PCI-e slot all the way, or worked its way out when you moved your machine. Also do the same thing with each stick of memory. Make sure the card and memory modules are in the slots they way the are supposed to be.

There might be a ground somewhere, try switching the RAM sticks and try to start with only 1 ram stick.

All good advice. Also, if you have another graphics card, plug that one into the same slot. The less variables the better.

Thanks for all the help. Is it possible to have two graphics cards in the mobo at the same time, run it using the other one and flash the new card when they're both connected? Or do I have to have only one card at a time?
 
Also there's one connector I got that I have no idea what it is - thin black and orange with a socket that connects to the graphics card on one end and two small black sockets on the other. What on earth is this? Thanks!

Unless it's SLI you can't have 2 at a time.

You can run as many graphics cards as you can fit(even pci, agp and pci-e at the same time with the right board), but be warned you have to take extra care when flashing this way. You must select the card to be flashed with a command line switch(if not you can flash a nice 8800GT into a geforce2 and it wont work any more), Why do you want to flash for? The best way to flash(if the current card will not post) in that case would be a pci card(from another company) that is so old it can not be flashed with nvflash. A S3 Virge DX is my card for this kind of thing. It has worked to recover several bad flashes too. SLI and Crossfire is in no way needed for running multi cards if those cards are not going to work together(they will run as 2 separate cards). If you want to run 4 screens you can use 2 cards to do this. I have ran a 8800GTX X1900XT and S3 Virge DX(and also a Geforce 2) at the same time

Now if you are talking about flashing the motherboard bios then there is not a worry, but its best to just use one card since the computer will only post of 1 card anyway.

Have you got the System to post again yet?

Also note in some cases 2 cards will share the same bandwidth since it may split 1 X16 slot into 2 x8 slots. This is not a problem for most things but for some high end cards there can be a performance hit.

The extra plug you describe sound like an audio pass through for running a HDMI adapter on the card.

anything like this?

Well since my last post I changed the RAM to the black sockets, and re-inserted the graphics card. Now the light comes on the motherboard to show it's receiving power but nothing else happens at all. Thanks for all your help but this is getting a bit complicated for a novice like me - I think I'll have to take it to the computer store.
 
Cheers!

have you tried to reset the bios?

Right under the green LED at the bottom of the board there should be a jumper in position 1-2. You need to move it to 2-3 for about 5 seconds(while the computers power supply if off and the switch has been pushed to discharge all caps[the lights should blink then go dead]). Then move it back to 1-2, plug in or turn of the power supply switch and try again.

Should look like this..

If I reset the BIOS does that basically wipe everything I've already installed - O/S etc? I could try that as a last resort so long as that itself won't make things worse!

All the BIOS reset does, is reset your BIOS to the default (failsafe) values, meaning it turns off any overclocking, and resets everything to the default boot device. It will not harm any of the data on your hard drive(s).

Don't worry, it won't do anything bad, unless you have a really important value that you had already changed in BIOS.

the only thing you may need to do after a resetting the bios is make sure your hard drives settings are the same(so if it was IDE. set it to ide if it was raid set it to raid ect..). If you did not change it when you set up the computer, you dont have to do anything this time.