Lifeless PC - Is it Power Supply or Board/Proc
 

I knocked over my CPU tower whilst it wsas switched on.

Everthing went dead and I can no no longer get the PC to power on. Not een the cooling fans fire into life when the 'On' switch is flicked.

I did a trawl of diagnostics sites and everything seemed to point 2wards the Power supply having failed. I've purchased a new PS yet I still have the same problem. I'm guessing power is getting from the mains to the PS and then to the motherboard cos there's a small LED light that comes on on the baord next to where the main connector from the PS plugs into the board. I've tried the mains lead on other devices and it works fine so it's not that either.

I've tried removing each of the PCI cards i have installed but this has no effect either.

Do any of you network techies know what could be the problem. I plan to get an identical P4 board that's currenty on an EBAY auction, but want to find out if this is infact my problem or could it be something else???

Again, basic symptoms are:

No life whatsoever when power is flicked on (no HDD spin-up or cooling fan activation. No lights on front of CPU box)

Only sign of power getting to board is small LED that lights up next to main board power connector.

I'm flumoxed....so need some help please.

Many thanks,

Guy

As the Hard disk is the most likely part to be affected by the shock, I would disconnect the power & ribbon to the Disk. With the HDD disconnected the machine should show RAM checks etc & complain no hard disk found.

If still no life remove all boards, drives etc you can. If still no luck I would agree it's probably the motherboard but probably worth reseating CPU & DRAM.

you need to get to a bare minimum to pin point problem item.
unplug hdd & foppy leads, take out all but the video card, and remove and refit ram and cpu.
alsomake sure that you have connected the small power on lead to the correct connector.
if you are getting power at m/board, is the led green or red on the m/board.
if there is a m/board etc problem at this basic level, you will hear a beap code, this is only basic info , but will narrow down the area at fault.
if you were local to me you could borrow my diagnostics isa/pci cards, these give precise diagnosis as to source of fault via error codes on led display.

if you also removed the video card you will get an error beep, indicating display adapter no present.
process of ilimation mate.

cheers
Robin

Thanks chaps.

Robin, The LED on the board is Green. Will try the HDD, CPU and RAM removal exercise in the morning and let you know how I get on.

Thanks again, Guy

(thank god for wifey's laptop)

is this a branded(hp/compaq etc) PC or a generic system.
If you know what make & model it is, let me know and I will update you on error codes etc.
Make sure that you have only got the PSU plug / video card/ ram & cpu fitted, to m/board and that power leads to drives etc are also disconected.
if you have no display and no beep codes or either one, chances are you M/board has failed, but it may only be a minor fault which has halted the system completly.

good luck mate.


robin

it could be the power switch it self
just tried it on mine. with the power on from the mains if i disconect the front panel on/off switch the likkle red led on the mother board is on but obviously the machine cant be powered up

the wire could have been dislodged in the fall or the switch itself could be damaged

im no expert by the way this is just an idea

Hi folks,

It's an Advent 3406 from PC World.

Done the power up with only the RAM and CPU (removed the video card too just in case) and there's no change in the result - no life whatsoever apart from the LED.

Hmmmmmmmmmm!!!

Looks like M/oard next then...

Thanks, Gc

you're getting quite short on options now guy.
You need to elliminate the power switch connector and the ram now.
like said in my earleir post, on the m/board there is a two pin connector for the power on/off - suspend function.
to be sure the switch is ok, it's working pull off the led from the pins, and short the two pins out with a small flathead screwdriver.
hold it on the two pins for 5 secs, remove then short out again for 2 secs.
this will ensure the m'board has been turned off fully,and rebooted correctly.
that will elliminate the switch or not.
also if you have two sticks or ram, remove 1, and try it with only one fitted, the swap around the dimms to check the other, see what comes from that.
Dimms can be easily damaged by indirect impact shock.
if you try the m/board with no dimms , is the result the same, I bet it is.
I have had this problem with several advents, they tend to use microstar boards in alot of there systems, and seem to suffer from these type of problems.

hope that helps abit more mate.

[Edited on 22-10-2004 by Red SPS]

Maybe the case itself has distorted or the plastic front has become dislodged just enough to stop the on of switch working.

My PC also went pop and after replacing the power supply - it did indeed turn out that the motorboard had failed in some way.

Turns out I managed to claim for this on my house insurance for an 'almost' identical PC that my little daughter poured juice into ;) :devil:

Frank