[Topgun]

so I get this new computer, assemble it and turn this sucker on.
first, the fans go on and... nothing. the keyboard doesn't receive any power and the monitor shows no signal.
so then I take out the pcie grfx card and replace it with an old 4mb pci card. everything works now... at least for the first few secands, then the computer turns itself off.

any help guys?

[Nuke]

sounds like you dont have enough power

but id be able to make a better judgement if you posted your specs.

[Topgun]

450 watt, the grfx card says I need a 400 or greater.

[Nuke]

well yea but thats how much your card needs, how much does your cpu and drives suck up?

add up all the wattages for every part in your system, you psu should be 100 or more watts above that (and more if you intend to upgrae in the future).

[Topgun]

basically I have this computer

http://www.cheap-n-easy-pcguide.com/build_your_own_cheap_computer.html

but with an 450watt PSU.

if he got it to work with 400 I think I can do.

[Nuke]

my old computer has about the same specs. it burned out its 420 watt psu and i put a 550 watt in and it runs fine.

[Topgun]

I just got the PSU today....

[CP5670]

The wattage ratings (and requirements, for that matter) don't mean squat. What actual model do you have?

[Topgun]

thermaltake tr2-430

my bad it's a 430 no 450.

[Scuddie]

Disconnect/remove everything except for a video card, CPU, keyboard, and memory.  Tell us what happens then.

[Topgun]

did that already... nothing.
EDIT:
Maybe it tunes it self off if it's idle? not likely...

EDIT2: I understand the behavior better now. the first time I startup, after it checks dmi data, I get "invalid boot disk" yata yata... if I ctrl-alt-del to restart it goes normaly until it's time for a boot disk... then it just turns off.

EDIT3: if I let it run the first time (when it's asking for a boot disk) it will turn it's self off in about 25 sec.

[DiabloRojo]

D'oh.. edit..
Just in case, but have you already re-seated the CPU and RAM?

Can't say I'm enthused about the brands, but eh.  I honestly don't think the PSU is the problem.  I think the mobo is the one saying 'nuh uh.'

Case in point to what CP said, I'm running a 7900GT with a dual core proc, two 7.2K rpm harddrives, SB-XFi, AND yanking power for LEDs via USB for my keyboard mouse and joystick.  All this from a supposedly 250 watt PSU.  (Dude, I can't kill this Dell!)  Eh, still relevant.

Do you have a Windows CD in the drive when it's doing this boot disk yammering?

[Topgun]

I havn't put in a cd drive yet.

[DiabloRojo]

Er, and it's a new hard drive too?  Might be a bios that doesn't want to do anything without a bootable drive so it turns off...?  Kinda guessing now.

Do you actually get the option to enter the BIOS?  (F2, F10 whatever).  I'm at least thinking the pci-E slot may have to be enabled first before that'll work...

[Topgun]

It says I can but when I try it, it just goes on like nothing.

my motherboard manual says if this hapens it is because my system overheated ?

[DiabloRojo]

Yikes!  Yeah... Make sure you have the CPU heatsink on properly, for sure.  Try taking off the heatsink and checking to see if there's an obvious 'bubble' showing no contact between the CPU heat spreader and the HS.  What kind of heat-sink are you using btw?  Or did you get a retail CPU (as opposed to OEM as the site mentioned)

[Topgun]

my temp reads at 50c, I don't think that is the problem.

[DiabloRojo]

But... where are you seeing that if it isn't letting you in the bios?  And if it is reading the temp correctly (which it should, considering the 3500s have the Cool & Quiet™ including an integrated thermometer in the die) then yes that'd be ok...  running out of ideas.

[Topgun]

it gives me the CPU temp at start up.

my guess is it has some sorta case detection thingie that turns the computer off when the case is open. but that does not explain the pcie thing...

EDIT: I am going to bed... keep posting ideas if you are on a different timezone, for those of you that are on est, then... I suggest you go to bed.

[DiabloRojo]

Eh... You should be able to have the motherboard sitting bare on a desk with all necessary components plugged in and still have it run without a hitch.  Only 'open case detection' I've ever dealt with has been on enterprise servers.

And yeah, the PCI-E vid card issue is still odd.

I just read on the comments for that mobo that the ram slots were numbered incorrectly... might try swapping ram from white to green or vice versa.  I also read another comment that described the EXACT PCI-E problem...