Computing not booting

Perhaps unsurprisingly I've run into problems with a new computer build (I've only done this twice before and both times there have been some kind of difficulties - the theory behind assembly is ok its just yet to go to plan in practice).

I'm at the stage where I'm just going to try and hand it over to some professional computer maintenance company, but it will be at least a few days until then so I have time to look around for extra suggestions about the problem.

Basically I've yet to get the new machine to post despite taking care when assembling it. All that happens with power is the fans inside the case begin to spin. The monitor displays a continuous "No Signal Received" error.


Are there any simple tests that can be done to help isolate the problem further (I've stripped the components down to Ram, CPU, graphics card, Memory).

Could it just be a lack of knowledge about computer assembly which has caused this error or is it more likely that something has failed (say CPU or graphics card)?

Should the motherboard be beeping (I've noticed that this can be used for diagnostics but this board doesn't beep nor does the board on an older stable computer - so it doesn't emit the expected single beep at boot up - could this just be the lack of a connecting cable?).

did you plug in your monitor?

mobo cant beep if theres no speaker connected to the pins on it

The monitor is fine as it works with other computers.

For the motherboard all I've connected is the case speaker connection. It's separated from the other front panel connectors (power, reset etc) so it's hard to make a mistake. Having said that a similar case which houses an older computer never beeps either (it boots fine but there is no beep at startup as would be expected).

Did you POST the components before install into the case?
Are all the parts new?
How much RAM and have you tried just a single stick?
Do you have access to replacement parts (most likely RAM or power supply) to try?

I installed in into the case before trying it for the first time (I wasn't sure about how barebone the system should be before booting).

All the companants in the case are new (all that was carried over from the old system was speakers and keyboard / mouse).

Personally I'm leaning towards a messed up processor or motherboard (as these are easier to mess up when installing).

I don't have anything to test with easily (I've a working older PC but it's dated enough that none of the companents, AGP graphics card or DDR memory for example, can be put into the new machine).

There's a second PSU in the old case which is working as it's powering the old machine without problems. It would take work to pull it out to try a swap though (which I have never done before) but I've held back as it's only a 400V unit which might not be enough to power the new machine.

The other PSU would certainly suffice to POST the (barebones) system though.
All you want to see is the PC boot into BIOS as this confirms that the motherboard, RAM, video and processor are good.

You needn't install the test PSU to do this- it can sit outside the case with just the ATX cable (and whatever other mobo connections are present) hooked up.