OK, Maybe I'm a total idiot, but . . .

[Woofmeister]

Hi there,

I finally bit the bullet and built my own computer from scratch. I'm using an Antec case (SLK1650B) with the included Antec 350W SmartPower ATX12V power supply. I'm using an Albitron PM266A PRO mainboard with a Pentium IV processor at 2.4 GHz. The installed RAM is Viking PC-2100 DDRAM in two 256MB modules. I had some othe components plugged in (Video Card and Sound Card) but when the problem turned up, I removed those to keep it simple.

I've installed all the components as per the instructions and now when I turn the thing on it only runs for about 5 seconds and then shuts down. I've tried reconnecting the power connections to the MOBO at least twenty times, have pulled out and reinstalled the CPU at least twice (no visibly bent pins on the CPU by the way) have pulled out the RAM modules and reinstalled several times. All of my fans are connected to the MOBO and running including the CPU fan on the heatsink. The fans just run for five seconds and stop.

I've swapped out the CPU with the one from my other functioning machine and I had the same problem so it's not the CPU. Now I'm baffled, is it the power supply or the MOBO? I've re-checked my connections to the drives on several occasions and those look right to me. I'm assuming my connections to the front power buttons are correct or else the computer wouldn't turn on at all.

Does anybody out there have any ideas? This is driving me to :wine:

Thank you for your help.

 

[DaTute]

Are the case buttons connected properly? Make sure reset is connected to reset and power to power and suchlike.

 

[MercenaryForHire]

Unplug all the non-essentials - like your drives - then plug your video card back in. Also, do you have both the regular ATX and the 4-pin ATX12V cables from your PSU plugged in?

- M4H

 

[Woofmeister]

double post

 

[Woofmeister]

Originally posted by: DaTute
Are the case buttons connected properly? Make sure reset is connected to reset and power to power and suchlike.

Yes, I think so. I reconnected them several times and also reconnected them backwards just to make sure that the manual wasn't misprinted. I've installed the switch marked "RESET SW" to the connector marked "RST" on the MOBO, the switch marked "POWER SW" to the "PWR ON" connector on the MOBO. I've also installed the Power LED switch to the 3-pin Power LED Connector and the the Hard Drive LED switch to the HD-LED connector.

I think that's right.

 

[DaTute]

Originally posted by: Woofmeister

Originally posted by: DaTute
Are the case buttons connected properly? Make sure reset is connected to reset and power to power and suchlike.

Yes, I think so. I reconnected them several times and also reconnected them backwards just to make sure that the manual wasn't misprinted. I've installed the switch marked "RESET SW" to the connector marked "RST" on the MOBO, the switch marked "POWER SW" to the "PWR ON" connector on the MOBO. I've also installed the Power LED switch to the 3-pin Power LED Connector and the the Hard Drive LED switch to the HD-LED connector.

I think that's right.

Yeah that's correct. It's "possible" the power switch may have broken, but it's unlikely with such new parts. Faulty PSU is another possibility.;
Have you tried the other suggestions? Like the additional 4-pin power connector on your mobo?

 

[Woofmeister]

Originally posted by: MercenaryForHire
Unplug all the non-essentials - like your drives - then plug your video card back in. Also, do you have both the regular ATX and the 4-pin ATX12V cables from your PSU plugged in?

- M4H

Did that already--still no luck. And yes, regular ATX and the 4-pin ATX12V cables are plugged in and I re-plugged them in several times just to make sure.

As you can see, I'm stuck.

 

[Amor]

I've got one for you that I actually had a problem with before with the exact same symptoms.

Make totally sure that your mobo is not sitting flat on the side of the case. You must have the 1/2 inch or something like that screw bolts that have an opening in their superior part for other screws. Those must be screwed into the base first to provide a mounting for the mobo to sit upon. Otherwise your system might short out and fry some important parts. I had that happen took everything out of the case set it up it worked like a charm. Then I put it back and dangit it did not work. Finally I got a clue somehow and did what I said above and it worked from there.

I hope that this suggestion helped you.

Amo

 

[mechBgon]

Amor is talking about these, if you need a visual

I just got done with a rough draft of a "my computer won't start" checklist and you can find that here if you want to see it. One of my first questions is whether your 2.4GHz processor is using the new Prescott core or the older Northwood core. On the processor's box, is it called a 2.4A? That would be Prescott. If it's the 2.4 with no letter, it's the Northwood with 400MHz bus, if it's 2.4B then it's the Northwood with 533MHz bus. This could be the whole issue, an incompatibility between the CPU, motherboard and/or RAM speed.

 

[Farmer]

mechBgon is always quite helpful.

Did you see anything on your display during those 5 seconds?

Though this would only isolate a faulty switch, did you try turning your system on sans switch? Like, with a screwdiver?

Amor is correct. You should take the motherboard out of the case, lay it flat on a peice of styrofoam padding (preferably on a box or something), install the RAM and video card, connect the power supply and monitor, and trying starting the system like that.

Or, as some have already implied, try a different PSU.