Hi I wonder if any one can help me? my machine recently died. Basically when i power on the machine the fan starts (there is no post - but there doesn't appear to be any speaker or connection for it to do so - this is another issue which is quite confusing i cant quite work out where this is supposed to be or whether the machine even has one) I have stripped the machine back to the bare bones just the motherboard,processor and a single module of ram (which i have also swap tested to no avail) but the machine simply wont start. The fan will whir for a few seconds (sometimes longer, sometimes shorter) and then the machine will simply cut out. I had a similar problem before which turned out to be the PSU but im not convinced that this is causing the problem this time as I replaced the PSU with a brand new one and this wasn't that long ago.... so i assuming this PSU should be ok unless there is an underlying fault which is causing the PSU to fail? to be honest im stumped at the moment and its quite frustrating.
any help would be much appreciated.

I don't think it needs a speaker to make the beep on post but it does sound like a power problem do you have a spare psu to test it with?

ah ok. Well its a fairly old machine so i should be able to pick a new PSU fairly cheap. IT seems strange that ive had two of these go faulty within like a year though.. Do you think its an underlying h/w fault? or maybe im just unlucky with them. Also should i not be worried about the lack of a post beep?

Speaker MAKES the beep sound. Some motherboards have on-board speaker. Looks like a big capacitor with a hole. The speaker connection is usually in the same row of pins where the connections are for the HD led, power button, power led and so on. Posting the model of motherboard would help.

Dead new PSU is possible. Also is possible that the motherboard fried it. To test the PSU you would need another machine with a same power conn. standard.

If it is stripped down to CPU PSU motherboard and 1 stick of RAM, you can go further. You can remove the CPU to see if there is ANY change in behavior. If not, that would be indicator that either CPU isn't getting power (ignore CPU fan... different source) or it is fried, but nothing is certain there. All speculations. Only way to be certain is to test it with known-to-be-good CPU.

I thought so... well im at work at the mo so not 100% sure details of the motherboard. I Will have a look this evening. With regard to the speaker - i thought there should be and i can see that there is an "empty" set of pins next to the connections for the HD led, power button, power led and so on. I will post a pic to demonstrate. The PSU was only a 350W so would it be possible that this isnt enough power as i have added to the original machine ( another HDD, A new sound Card, A wifi Card, and Several USB Devices), but then again it has been running ok only recently started randomly switching itself off and now its stopped turning on.

Another question I have is the processor is an Old AMD AThlon XP 3000 and im not sure the best place to go to get a new PSU ( i will try this first) Ive heard that AMD are quite stringent about PSU standards.

If you mean that the AMD is power-hungry CPU, I doubt that it makes significant difference on the whole PC consumption.
350W should be enough to run the machine you described, but USB devices (if not powered from outside source) can be quite a load on PSU.
Some older VGAs are real loads (ex. NVIDIA 6600), while newer ones (ex. NVIDIA 7800) have such technology that is not so power-demanding. I suppose that you have on-board VGA.

Anyway, PSU is the cheapest part of bare-bone PC..$50 tops. Maybe more, but not much more.

Actuially i wonder if that could be the problem... im actually using a Nvidis Geforce 5600fx and funnily enough i did notice when i first started looking at the possible causes for the problem it seemed to be that whenever the Monitor was unplugged (from the DVI port on the graphics card) the pc would start ok. This happened quite a few times, but eventually it got to the stage where this didnt even make difference.

Maybe your VGA is faulty... you will need beeper to eliminate VGA as a cause. The procedure is simple.
(After the beeper is installed)
Unplug the VGA and switch it on. You should hear beep-code for faulty or no VGA. (usually 7 short and one long beep). Real faulty VGA can halt the boot without any beep-codes, so don't let that confuse you.
If you hear the beep-code, that means that the rest is working. In other words, VGA isn't. Sometimes, all it needs is to be reseated.

thanks for the suggestion but if i have tried the machine with just the barebones (no VGA card) although i dont have the beep to see if that is an issue or not? i will need to have a look at why its not funtioning... i might post some pics to get some advice. I will have alook tonight.

ok, i hope this pic will help to clear things up a bit.. sorry about the quality. I assume that the cable for the motherboard speaker should be plugged on the end next to the power/fron led cable? but there is no cable there and as fas as im aware there never was? can some please advise??