Any PC hardware experts here, please?

[rossi46]

..because I've pulled the cpu off of my motherboard

It more or less came straight off without protest. I cleaned the dust from underneath it and it popped back into place no problem. There are what looks like 500 gold coloured pins underneath, but they all slot home without incident.

Problem is, when I press the power button on the from of my machine, nothing happens other than the briefest fraction-of-a-second of life then nothing. I realise that this is a safety measure designed to protect the components, but how can I fix this?

Cheers in advance for any help.

The spec is Fujitsu Seimens 3.4/1G

 :getmad:  :crazy:

[meega]

There is normally some sort of retaining clip/lever that locks the CPU in place in its socket. If yours 'just pulls out' then there could be something seriously wrong... Once the CPU is locked into its socket, it is meant to stay there.

You are supposed to free it by working the retaining lever... You didn't really just pull it out, did you?

Also, could you provide a link to some info about your machine?

[Zac67]

If the machine seems to start for a split second and then shuts off, it's usually an electrical short.

Have you verified that the CPU's orientation is correct and no pins are bent?
Checked seating of AGP card? The two staggered rows of contact are an ample source of trouble.
Replaced thermal paste? If you re-used the old grease with a Socket A CPU (Athlon/XP/Duron), you might have killed the chip. Or you might have cracked the die when replacing the cooler, sometimes that shorts the power.

PS: FSC 3.4 GHz probably means a P4 - are the pins in the socket (LGA775) or on the CPU (Socket 478)? The LGA sockets are very easy to damage...
But it's next to impossible to remove an LGA775 CPU by accident.  :-?

[kd7ota]

Zac67 wrote:
But it's next to impossible to remove an LGA775 CPU by accident.  :-?

I could see that the LGA775 is next to impossible, but with Socket 478 its possible because ive done this 3 different times with other people's computers. The stock thermal pads will just be stuck to the CPU like crazy after having it a few years. When I went to take off the heatsink, the CPU came right out of it, though the CPU's pins were still perfect...

So when you take off a heatsink, just be sure to pull straight up, not to the side.  :-D

[Homer]

I would take a look to see if there is a retaining lever, as you may have forced the inside of the socket into a bad position. If it does have one, and you can release it then re-clamp the cpu, that may do it (as long as you have orientated the cpu correctly to the socket. This is usually best done with the heatsink off the cpu.......

[Zac67]

kd7ota wrote:
I could see that the LGA775 is next to impossible, but with Socket 478 its possible because ive done this 3 different times with other people's computers.

Yes, very easy actually. You should try twisting the heat sink a bit before pulling to soften the thermal pad. Works most of the time.

@OP
If that happened to you:
- clean CPU / heat sink from thermal pad/paste residue
- check pins - they must be 100% straight
- open the socket by lifting the lever
- carefully plug the CPU to the socket, note orientation
- hold CPU in place & lock with lever
- re-apply thermal paste, sparingly
- mount heat sink, make sure to orient it correctly
- don't forget the fan power

[jrkenn]

As above check your lever and pins. You may also want to use some air to blow out the socket, just be sure not to tilt the can. Maybe something got in there. Make sure it wont go any other direction, usually it will only go one way but with most stuff being "Made In China" who knows. LOL  

[Ronmor]

I found in more than 1 case the power wires on the floppy  drive were plug in wrong. :-o

[Firedawg]

@rossi46

Not familiar with you particular system, but I know, as everyone else has pointed out, that if your CPU socket does not have a clamping lever (located @ the CPU socket) for which to clamp those 500 pins in place then you are not making the necessary contact to the MOBO, and the system will not boot.  

Also, to consider the proper heatsink/Fan install (you did not mention one).  If this processor is overheating this will shut your system down quickly as well.  Make sure you are using thermal paste with your heatsink/fan. Reminder, too much thermal paste can burn up your CPU, so just a dab will do yeah spread thinly over the processor.

Once your CPU is seated properly, and the system is still not booting properly then the system memory would be my next area to investigate.  If you have a bad stick of RAM or it is not seated properly this can cause your system not to boot.

After RAM checks out then individual PCI, ISA cards can be removed from the system then a boot tried to see if they are causing the problem.

Hope that helps some.

[SamOS39]

Did you wear any kind of antistatic protection when handling the chip .. not sure if this matters..?

[meega]

I have never used an antistatic strap, and I have never had any problems. I also don't shuffle my feet about on the carpet while I'm working on a machine... A good way to proceed is to:

Leave the machine plugged in to the mains, but turn it off at the wall socket. That's right - think about it - it is still earthed. This is not strictly necessary, but in electrical terms it is quite safe.

Do NOT work inside the machine unless you are sure that the internal power supply is completely drained... Switch the machine on and off a couple of times to make sure, or just switch it on (N.B. it is still OFF at the wall) and leave it for a while. There could be quite a bit of reserve capacitance in there.

DO touch the metal chassis of the machine before you fiddle about inside it - this will discharge any static on your body to earth (hopefully through the still plugged-in mains lead, but if not connected that way there is still enough metal in a good case to do the job). Do this frequently - if you have modern materials in your clothes they might create static just by your moving about. Simply touching the chassis every now and then will prevent any build-up of charge. If your clothes do create charge in this way, change them for something less fashionable. :-)

I would rather make sure I had earthed myself through touching the case than wear an antistatic strap. If you have to get up and cross the room then you will probably need to take the strap off to do so, and walking on a carpet might create enough charge to damage some components. It is swifter, easier, and more convenient to simply make sure you earth yourself every time that you prod about in the machine.

[whabang]

I agree with Firedawg:
Remove the RAM modules from the system. Most computers emit beep codes when there is no memory in the RAM slots, so if it doesn't, then you can be fairly certain that either the motherboard, or the CPU is defective. I'd still take out any other components connected, just to be sure, though.