pc power problem

[thumpertwinkle]

PC won't come on it's dead!

There is a little led on the back near where the power supply plugs in which illuminates green but when i press the power on button on the front the led goes out and the pc does nothing.

I am not sure if one of the kids swithed it off at the plug , there is a bit of confusion (or denial) here, if they have could this have caused the problem and what could the problem be?

Any help appretiated.

Thanks

[unrealuniverse]

it sounds like a short, try to find the problem, unplug the PSU for 10 seconds and then try it again.

[thumpertwinkle]

Thanks for your suggestion, unfortunatly it has made no difference.

I have taken the side off the case and lokked inside, I cannot see any obvious signs of damage, burn marks or smell of burn, the only thing that strikes me is the fan is full of dust. I have had the hoover on it but still no difference.

Please help!

[thumpertwinkle]

it sounds like a short, try to find the problem, unplug the PSU for 10 seconds and then try it again.

When you say unplug the psu do you mean actually inside the pc, unplug from motherboard?

[thumpertwinkle]

I have been on the pc manufacturers website and gone through their troubleshooting page on power problems and I think the psu is damaged due to a power surge (child pulling plug!) I cannot find out though on their site which is the replacement psu, any help on how to find out what the replacement part is.

[ArmagoN]

is this a dell machine, Orange flashing power button ...... Dead Psu
Orange solid light ..... Dead Mother board.

That is if it is dell.

[thumpertwinkle]

O.K Here it is, I have tried everything. The PSU seems to be O.K as I have had a voltage meter on it and it is sending power through to inside of P.C. I have unplugged the floppy, coth CD drives, hard drive, removed cards and memory - still DEAD!

Could it be the on/off switch itself as it is when I press that as the little LED on the back of the p.c goes out? But I don't know how to test if it is that. Do I unplug it inside the p.c and using something metal touch the prongs it plugs into to?

Any suggestions greatly appreciated as you can tell I am really stuck here.

[icq3800846]

1) Check motherboard header leads are attached to the correct pins IE the SWITCH and RESET leads are attached to the SWITCH and RESET pins on the motherboard.
2) Check the ATX power connector (20 or 24 pins) is firmly attached to the motherboard. Unplug it and plug it back in again.
3) Check the auxilliary 12 volt connector is attached firmly, unplug and plug back in again (4 pin or 8 pin near the CPU)
4) if this doesn't work, you will have two options. One is to bypass the power switch in the case. To do this you remove the ATX power connector and short out two of the pins..... if it comes to this there is a link I can give you which shows you which pins to short, but personally, I don't much like the idea of doing it and the probability of the actual case mounted on/off switch going faulty is fairly remote. The other thing to also try is to take EVERYTHING off the motherboard, memory, processor, hard drives and all expansion cards. Remove the BIOS backup battery and unplug the power supply altogether from the mains, wait a few minutes, and to be on the safe side clear your BIOS as described in your user manual, then install the BIOS battery, plug the power lead back into the wall and try booting with ONLY the motherboard attached and wired up.

Hopefully your motherboard will start to produce a frenzy of error beeps to say, "Hey there's no memory, hey there's no processor, hey there's no graphics card" which will be great, because that would prove the motherboard and PSU is working.

If you get that far, it's a question of replacing each item one by one to see which one makes the system fall over.

[thumpertwinkle]

This sounds very much like what I have done already only i didn't removethe bios battery and how can i clear the bios whithout it swictching on? I don't think it tells me that inthe user manual.

[thumpertwinkle]

This may sound really silly but can I replace the motherboard, pentium 3 socket 7, with any other socket 7 board? I have seen some on e-bay. Also the processor looks like it doesn't come out, would this be correct?

The desktop is now the childrens you see, as I have myself a laptop, which I am not seeing much of since the desktop broke! So I do not wish to be spending loads of money on it now as it is plenty good enough for what they do on it - MSN and research homework mainly.

Thanks.

[icq3800846]

The BIOS is normally reset by changing the position of a jumper on the motherboard which is usually situated right next to the BIOS backup battery. Clearing it is meant to reset the BIOS back to the factory settings as when it was new, although I have seen a BIOS retain it's settings after having done this, and the only sure fire way to really do it is to unplub the system from the wall socket, take the battery out for a few minutes AND clear the BIOS with the jumper on the motherboard.

Pentium 3 came in slot 1 form when they were new for a very short time, and the bulk of them came in FCPGA socket 370 a little later on.

Socket 370 boards can be replaced IF you can still find one.

I would suggest looking for a motherboard, memory, processor and graphics card bundle and upgrade the lot of them. If you're on Socket 370 Pentium 3 then an upgrade to the lowest 2.0Ghz Celeron that's dirt cheap, or an AMD Sempron would see a bit of a performance boost and would bring you up to date a bit more.

You should be able to get a cheap upgrade of motherboard, processor, memory and some sort of graphics card for 150 quid, and 200 quid would probably buy you something current that would be upgradeable in small steps as and when you could afford it.

Regards the processor, some computer manufacturers DID used to glue the processor into the socket.

Socket 370 is ZIF socket... zero insertion force. Once you remove the heatsink, there is a little metal arm which needs to be gently unhooked and lifted up, the processor will then lift out with no force whatsoever. If it doesn't, it may be glued in place.

[thumpertwinkle]

I took the fan off the top of the heatsink and the heatsink is packed with dust! I am wondering if the processor is at fault - overheated! Anyway I cannot release the lever that is holding the heatsink in place, I cannot get it to unhook, any suggestions (it is a P3 socket 7 type)

Thanks

[winactive]

You should be able to remove this with your fingers (i.e. without tools).

One side will have a bigger thumb guide, holding the heatsink evenly, press down and then away from the CPU to unhook the heatsink clip from the ZIF socket.

If you can't achieve this with finger pressure, use a flat-bladed screwdriver, but be sure to use one that doesn't suffer from 'driver slap' when you put it gently in the thumb guide. (i.e. it should be a snug fit and not likely to slip when you apply downward pressure).

Be careful when pointing and applying pressure on the screwdriver as slipping through and making contact into the motherboard PCB or it's components can easily mean the motherboard is transformed into a novelty paperweight.

The socket 370 fan clips should pop off with finger pressure though as they're not generally as tight as the Athlon socket A clips. If at first you don't succeed, you're probably doing it wrong! Check you're using the correct side of the clip to release it.