Problem with a computer I just built. Can anyone help?
 

Everything is connected properly, and all the components appear to be working (no loud hisses or whirring etc). However...

The motherboard supports P4 up to 3.6GHz, and the case can house P4 up to 3.6GHz with a 350W PSU. I switch the computer on at the mains, and the green LED on the motherboard comes on. Then, I switch on the power on the front of the computer, and the fans start to spin... then everything shuts off in about 1 second. The fans stop, the hard drives switch off, etc. The motherboard doesn't even beep. But still, the green LED on the motherboard stays on. What could be causing this?

I tried removing the memory then powering up, but still the same thing happens.

Here are the specs...
P4 2.4GHz Prescott 533FSB 1MB Cache
Asus P4P800S-SE Motherboard
512MB Corsair DDR Ram PC3200
Seagate Barracuda 80GB / 7200RPM / 8MB Cache SATA

Any help is HIGHLY appreciated. :)

heat maybe?

REmove cables to all drives disconnect everything you dont need and try again

Check if you got anything loose... Try disconnecting everything and reconnecting it firmly in place.

You might have a defective memory chip. I had one when I tried building my computer. Drove me crazy til I realized I had a defective chip.

Is the CPU being reconised? (POSTing)

You'll know cause you'll hear a single beep.

If so, it's a heat issue.

If not, it's probably an issue with the fans telling the motherboard that they are not spinning fast enough and the motherboard is shutting itself of to save the processor.

This is meant to work when a fan breaks so the chip doesnt fry.

how many harddrives are you running?

I removed all cables and put everything back. Same results.

I removed everything except for processor and memory and essential cables (power). Same results. Then I removed everything except for processor and essential cables. Same results.

Should motherboard + processor still power up properly, and stay on (i.e. fans keep going around) if there is no memory present?

Try booting with mobo+proc+ram+video card...

I don't hear any beeping, but the CPU fan does spin for 1-2 seconds before stopping. The same happens with the case fan if it's connected.

I'm running just the one hard drive, but I did disconnect it and tried to power up, no luck. :(

Check to see if you bent any pins on your processor. I did that once and had the same prob as you.

If your Motherboard has multiple slots for the CPU Fan than make sure you have the fan plugged into the first slot.

bad power supply

If you have eliminated all peripherals and you aren't even getting to the POST (Power On Self Test) screen I would think the MB is bad.- the ROM chip on the MB is responsable for the power on self test, which is the first thing to run on boot up.
but its just a guess.

I was going to say, make sure you have your CPU fan plugged into the cpu fan header and not a case fan header. Sometimes mobo's will power down instantly if nothing is plugged into the CPU fan header.

Hmm.. with all You've said so far, I think the problem is with the CPU...

If it's not that it's broken, it's probably running with an overclocked Front Side
Bus speed (FSB speed).

Your motherboard seems capable of running the P4's with 800MHz FSB whilst
the CPU You're using is a 533MHz-model.

Look it up dude, I think You're motherboard is trying to run the CPU at an FSB-speed of 800MHz...
There should be like a jumper/jumperblock on the MoBo where You can set the FSB to 533 instead.

Before changing M/B if defective, do Clear CMOS ... Maybe a previous setting is in there ....

Make sure the mb is not grounding out on the case.

excellent point!

maybe just take your time and reassemble from scratch.

Thanks guys, lots of useful feedback.

I checked the processor - no bent pins.

I followed the instruction manual for the mobo and cleared CMOS.

About the overclocking. I checked the instruction manual, but I couldn't find anything about setting FSB with jumpers. The only thing it says, is use BIOS to tinker with overclocking settings.

I tried a different power supply from a different machine (which I know is working) -- no luck.

The CPU fan is plugged into the slot labelled CPU_FAN

Either it is bad RAM/MOBO/CPU ...

Try swapping all of those parts (at different times) and eliminate them one by one and see what you're left with.

Ok, that part is automatic then... the motherboard should detect what
processor it is and run it at the correct FSB speed.

I feel clueless now.. sorry :(

Is the RAM seated properly?
It's easy to not push it down well enough.

Oh yeah, just came to think about this as well:

I haven't played around with P4-machines but aren't You supposed to connect an
additional 4-pin power-plug hanging out from the Power Supply to the M/B also?

In case You missed that part... it's supposed to provide extra "juice" for
the CPU.

Ive only played with AMD machines but my power supply has this plud. I could see myself forgetting that if I built a p4 machine.

Same here both on the only-AMD-part as well as could-see-myself-forgetting-that

Cheers to good ol' AMD by the way :winkwink: :glugglug

Yeah, I connected both the 20 pin and the 4 pin power plugs. No luck...



However, I just hooked up a humble old 250W PSU and it is now working perfectly!

Thanks, I owe you all drinks. :glugglug

First P$ were like that.

But the latest I assembled didn't require or even have a receptacle on the mb for that.

I had once a problem like that with DDR ram; it was bad. I put SDRAM ( had both options) and it booted np...

Very frustrating.

One simple thing that can sometimes be the culprit. Replace the MOBO battery with a brand new one. Sometimes these boards have been sitting on a shelf for a long time before getting into the store and sold.

But it sounds more like you don't have things configured right either a jumper on the board, or in the CMOS settings.

You might have a board with a short in it.

Its fairly rare to have a fucked up CPU if you bought it from a reputable place. If you bought it from one of the discounters it could be a CPU which is labeled differently than what it really is.

Heat issues shouldn't cause a shutdown in a second like that if its powered up cold, so I don't think that its.

Good to hear! :thumbsup

Cheers :glugglug

I'm really surprised how many problems stems from the PSU's nowadays.. weird.

DirectFiesta: thanks for the update on that, guess Intel began feeling like the ugly duckling with it :)

I helped my little brother assemble a comp. with both SDRAM & DDR support
a while back, we got the exact same problem!

Then we tried with a more powerful PSU, just 50W more, and DDR.. Voila! :)

I'm beginning to think there are way too many shitty PSU's manufactured today.