Computer failure. Help!

[tonyrobbo]

While watching a movie on my computer last night, the screen just went off and the no signal message came up, also the HDD light was constantly on even though the computer was not accesing it.

I tried a reset but the reset button wont work, so i turned the computer off for a few minutes and then back on, still the same.

Also the computer doesn't beep on startup or even go to the bios.

I think something must have failed, i built this system myself a couple of years a go (one of many) so i just need help identifying the failed part.

Any ideas?

[The village idiot]

Bad hard drive, IDE cable or IDE controller. Bad processor. Bad ram.

Pull out all the PCI/AGP cards except video card. Disconnect all IDE devices. Disconnect floppy and USB, and firewire devices. Try to boot to BIOS. If not, try swapping memory from another machine/spare memory and try again. Swap processor with another of the same socket type. Swap AGP card for cheap PCI card, or ISA video card. Swap powersupply with one you know is working. If none of that works, then the main board must have a problem.

Add cards and devices back one at a time until problem comes back. And make sure all the fans are running. Sometimes when the processor overheats, it will lock the machine until it cools down.

[Solarjetman]

As a guess, I would say either a failed Power Supply or Motherboard. LEDs being lit mean the power supply is giving some power, but the other voltage lines may not be working.

What you need to do is strip almost everything out of the computer. All that should be left is the CPU, RAM, Motherboard, Power supply, and video card (even unplug your hard drive). Also unplug everything except your monitor and keyboard.

Now turn on the computer. The above is the absolute minimum you need to pass the POST (actaully you could get away without the keyboard and video card but then you could not see what is going on, and some BIOSes will start but not finish the POST without a keyboard). Of course if it works you will get a "no boot disk" error but that is expected.

If you successfully boot, then re-attach parts one by one until it fails to finish the POST. The last part to re-attached when it fails is the bad part.

If you never could boot with the minimums, try removing the video card and boot (listening for POST sounds). If it works, then its your video card.

If none of the above identify the problem, you will need extra tools to test the remaining parts, or spare parts to replace them one by one to find the culprit. In that case it is either you motherboard or Power supply. If it was your CPU or RAM it would give an error stating so (not sure about the CPU, but I think so).

Hope that helps. Like I said, it is probably your motherboard or power supply. And just so its clear, even though you sound like you already know this, it is not a software problem. It is definately hardware.

[tonyrobbo]

Thats just what i was thinking either mb or power supply but the power supply is a 300w only about 6 months and the mb is a Shuttle AV40 about 2 years old?

Is this power supply big enough for my system?

P4 2.4
512 ram
Geforce 4 myVIVO
Audigy 2
17" monitor
Broadband modem
2 HDD
cd drive
dvd-rw drive
1 floppy
joystick

if not could this cause the mb/power supply to fail?

Thanks for your help!

[Solarjetman]

Is this power supply big enough for my system?

I would say you don't have enough. Your power supply is probably severely taxed. The CPU alone takes 60-80Watts away from your total. A DVD burner can take up to 40, and a Geforce 4 take alot also. I would not recomend anything under a 350W for a Pentium 4.

I would suggest getting a 400W to replace it. That way you have some extra overhead.

And yes, an overworked power supply can cause system failures. Even worse, it can actually damage computer components when it fails. It could easily explain the cause of your problems. I feel the power supply is one place where you should never skimp. It is just too important. I have a 430W myself.

[tonyrobbo]

Well i tried removing all the different components and it made no difference, so it looks like either mb or power supply.

I had a feeling from the start it was the mb but because the power supply is not large enough, i will replace both.

I will get a 400w as you recommend and probably a Abit IT7 Max2 or Gigabyte GA-8PE 667 mb, would this be a good replacement for my shuttle AV40.

Thanks again!

[Solarjetman]

I can't really give you any worthwhile advice on if those are good motherboards. I am not current on motherboard trends right now. But I do have a suggestion for you. Unless you are really wanting to replace your motherboard, may I suggest you first buy a power supply and try it out to see if your computer starts working? You may get lucky and your MB is fine.

Also, if you do end up buying a new one, Windows is very bad at handleing motherboard changes. You may want to try and get your computer up and running to backup all your stuff before atempting the motherboard swap. Just in case.

[The village idiot]

That 300 watt supply is plenty. Especially with everything unplugged. Generaly if one of the voltages is not good, you will not get the power lights. The mobo samples each voltage and then reports back to the supply that all is good. If it isn't good, the supply will shut down most of the voltages.

You could also try a BIOS reset. Sometimes they get stuck. Besides it doesn't cost anything to reset the Bios.

I would pull the processor, and check for dust around the pins and on the socket. Pull the ram and check for the same. Then try again.

[Solarjetman]

That 300 watt supply is plenty.

I don't see how you think 300 watts is enough. I ran the numbers using average power guidlines assuming 3 case fans, a heafty video card (since its Geforce4), and a CPU cooling fan and recievied a 314 watt top usage.

I did not even take into account if he may have any firewire cards, RAID, USB ports, or anything else. Add to the fact power supplies often are not labeled by the maximum sustainable wattage (with the exception of Antec's TruePower series), but rather a short burst top wattage. A 300W PSU would probably only be able to keep up with 270W for an extended period.