PC tech help needed - system building

[Hidden Character]

Don't you just hate it when you get your new toy out of the box and it doesn't bloody work. I've just assembled myself a new PC with the following bits:

Asus A7V8X-X SKT A KT400 8x AGP DDR Sound/lAN/USB 2.0 motherboard
AMD ATHLON XP2600+ 333MHz FSB - Thoroughbred
Coolermaster CP5-8JD1F-0L Upto XP3200+ Silent Skt A Heatsink & Fan
Crucial PC2700 512mb DDR 184pin DIMM
JNC 4JA 140i(a) Grey ATX Midi Tower Case 300w PSU

To which I added, from my old system, all tested and working:
Geforce 2 MX
Sony DVD
TDK CD writer
27GB HDD
monitor etc

When assembled the green power LED on the motherboard is lit. When the power button is pressed, the PSU and CPU fans, and HDD, all start and then stop after 1-2 seconds. Here is what I have checked:

* all connections
* factory default motherboard jumper settings
* IDE jumper settings
* disconnected primary IDE, then secondary IDE, then both
* took the usual precautions against accidental damage
* plugs/fuses

None of the above had any effect whatsoever. This is particularly frustrating for me as I have built many systems in the past with no problems - I suppose my dumb luck has run out. Any advice would be greatly appreciated... at the moment I'm back on my old system which is about five times weaker than what I've just paid for! ft: Hopefully it's just something simple. Please help before I chuck it out of the window!

[shogun2k]

test EVERY component new or otherwise, swap round the psu's first , as that seems a likely cause and then go through all the other componnets, replacing the geeforce with a old 2d/3d card for instance or bits from a working machine.

Time consuming but you will find your problem, also check the ram is seated properly and swap that around , that can cause the problem you described

[Ciaran]

Check you have you CPU fan connected to the right fan connector. If its not then the motherboard shuts down for "safety". (It should be in your manual)

If that doesnt work then try starting up with only the bare essentials.

[dmg]

when the system starts listen for the beeps, these will give you an idea of where to start in many cases. You'll find the meaning of them in your mobo manual, look for POST.

[Kirby]

Check (and i mean REALLY check!) that the motherboard isn't being shorted by the metal mounting pins on the case. This has to be pretty much the number 1 issue i have to fix for people when they've built new systems.

I remember one really well designed case used metal posts welded onto the case rather than the screw in types. In the end i had to hack off the offending posts with a saw.

[Hidden Character]

Thanks for the replies. Here's a mini update:

* tested as many components as possible
* tried a new power supply - no different
* checked fan connections - ok
* system doesn't get as far as making any beeps
* Kirby - I'll check the mounting pins - they aren't integrated but it is a dirt-cheap case...

I'll do one more build, then the motherboard is going back to the supplier because that seems the most likely culprit.

[Hodge]

Do you have a spread spectrum option in the bios? if you have disable this as it basically just there to stop you frying your cpu. It can also stop your computer from booting if theres the slightest increase in voltage and basically does more harm than good.

[newmiyamoto]

Thanks for the replies. Here's a mini update:

* tested as many components as possible
* tried a new power supply - no different
* checked fan connections - ok
* system doesn't get as far as making any beeps
* Kirby - I'll check the mounting pins - they aren't integrated but it is a dirt-cheap case...

I'll do one more build, then the motherboard is going back to the supplier because that seems the most likely culprit.

from the spec of the board and the graphics card i'd say its probably because of the high voltage card which causes the motherboard failsafes to turn the machine off after a few seconds.