turns on then off

hi
my other desktop suddenly stopped working, i think my lads giant pup crashed into it?..... anyway i bought a new power pack.... took the fan off the psu cleaned all the fluff off.... removed the thermal paste replaced it with thermal adhesive tape.... bought a similar mob...tried it with the bare bones... nojoy
my question now is do i get a new psu? ... heatzinc and fan?

 

Disconnect and reseat all the cable connections (don't just wiggle them), at the drives and the motherboard. Take out and reseat the RAM (try the modules in different slots or singularly if you can, but if there are 4 modules, they will probably be in matched pairs.

I am not sure what you mean by "power pack ", but if it is a few years old, look at getting a replacement CMOS battery (CR2032). Read in the motherboard manual about Clearing the CMOS, it might have jumpers or you remove the CMOS battery.

Watch carefully what happens. Do any drive LEDs flash?

Start-up with the case open. Watch that all the fans spin freely (you say that it turns on, apparently briefly).

I could not see how a "bump" could make the PSU break down. Is it a standard PSU or a specially shaped one? You should be able to borrow a PSU from another computer and connect it's cables onto the motherboard and drives temporarily for testing.

If you suspect a bump, the CPU should not be affected, nor the PSU. Cables can come loose though and hard disk drives would hate that, especially when running.

The last thing I suspect is the CPU.

Matt

 

hi by powerpack i should have put psu. i was getting mixed up with cpu. i have already tried most of you you have suggested except changing the cmos battery. a led light does light up but when i press the on button the fan on top of the cpu spins for a second then goes off, pressing the button again nothing happens... so i disconnect the power then turn it back on same thing happens again. i will try again with everything connected hdd video card etc...

 

your description does sound a bit like a faulty Power Supply.
You can buy a Power Supply Tester at a very reasonable prize and test the PSU.

 

Which one? Does it flash or does it stay on until the computer shuts down?

You can try disconnecting all of the drives.

Did you "Clear the CMOS "?

You need to create different startup conditions, so that the you can get a reaction from the BIOS telling you what is wrong. Replacing the CMOS battery is my best suggestion at the moment.

You seem to have tried a different PSU, is that right?

Matt

 

yes i have a new psu.

 

You will need to tell us how you going with the suggestions, although you say you have tried most. How are you going with clearing the CMOS and getting another CMOS battery? I suppose you have tried disconnecting drives? If there are any added devices, like PCI cards, remove them.

You can try pressing the "Enter startup configuration settings" (BIOS) key, usually F1, F2 or Del.

If you want us to make any further suggestions, you will need to actually describe what you have done.

The BIOS might have the wrong settings for the CPU or a problem with the RAM. You will need to clear the CMOS (reset the BIOS). An LED comes on, which says to me that it is trying to identify the hardware. It might be having problems with one piece of hardware.

Matt

 

hi i still haven't bought a new cmos battery... from the start i have tried with no drives or pci cards and with nothing at all.

 

Do You have an UPS? A failure of it can cause it.
I live in Uganda where You need an UPS.
For some PC not pushing long enough can on the on-knob can cause it to.

 

If it doesn't involve a UPS, you replace the CMOS battery or "Clear the CMOS ", it probably ends up as a motherboard problem.

 

hi whats a ups is it some kind of power surge?... the mob is new.

 

UPS is an "uninterruptable power supply ", it has batteries that keep the computer working when the mains power has an outage. It allows you to save any work and shut down or keeps it going through a short blackout.

 

hi i bought a new cmos battery cleared the cmos, nothing has changed so i am giving it a rest for a while. i would like to say thanks for your input.

 

I was rebuilding an older machine for the fun of it and just experienced this same problem.

It worked just fine until I hooked up a case speaker, then began to shut down as soon as I would start it up.

I evidently loosened the power switch wires and did not notice.

As soon as reseated the wires and then tried it again, it did the same thing until I changed where the CPU fan plugs in.
The Mother Board had two places....maybe not worth mentioning.

Just giving this for whats it worth, if anything

 

Hi neilstan, when you said your lads giant pup knocked the computer, is it a Tower unit or Desktop? Was it knocked over on the floor or did it crash onto the floor from a desk?

Was it going when it was knocked over? The Hard Drive is the most likely unit to be damaged if the comp was running. The PSU should withstand severe bumps as everything is normally firmly attached inside it.

As Matt suggested earlier, ALL leads and connections need to be checked thoroughly by complete disconnection and reconnection.

It would help if you filled in your System Specs so we would have a better idea what your comp is. Neil.

 

hi when i said it could have been my lads pup, (my pc went around the same time that he brought it round) i thought it must have been him but never seen him crash into my desktop, at the time i couldn't think of any other reason.
my mob was an asrock k7s41..i bought a k7s41gx ( the nearest match) after i messed the other one up.. i didn't have the mob ******* down one time and a bit of smoke happened when the mob moved a little but the cpu fan spun? i got rid then.

 

Hi neilstan, I'm having a bit of trouble reading your Post. You state 'mob' which is motherboard or m/b? I can see from your info: Asrock K7S41GX that you have a Micro ATX m/b.
You stated that the m/b smoked and you replaced it. That would be your K7S41 replaced with K7S41GX?
Have you renewed/replaced your AGP Video card at any time?
The manufacturer states that the use of a 3.3V AGP card may cause permanent damage to the m/b!!!
There is also a warning not to overclock as instability and damage may occur.
Have you carried out Matts earlier suggestion to thoroughly check all connectors?
The only other possibilty is that the CPU is cooked or blown. The only way to check is with another GOOD CPU of compatible value installed correctly. Neil.
http://europe.asrock.com/manual/K7S41GX.pdf

 

hi sorry about the late reply, i never seen the pup smash into my pc i blamed it because i couldn't figure out why it had stopped working? its a desktop and the mob was a k7s41
until i changed it for a k7s41gx. i have just looked up the specs on the k7s41gx and found that the memory differs from the k7s41, ones pc3200(ddr400)/pc2700(ddr333)/pc2100(ddr266).
the k7s41gx starts at pc2700(ddr333). maybe i need new memory?