No beep, no post, no display

Can u swap the PSU's?

Did u do any HW upgrades on the PC?

Haven't got another PSU, computer is original spec.

Did u do any HW upgrades on the PC?

No beep too?

CMOS battery may be low on power.
I would replace the battery ... 2032CR model

No beeps, CMOS battery good, (I thought that just kept user defined parameters in memory but wouldn't prevent initial boot).

So battery was exchanged? It does more.

Yes new battery, also reset jumper.

Did it died in the middle of something or it just didn't start after proper shutdown?

Didn't start properly after proper shut down. Sister said it came on and a blue screen message appeared but shut down before she could read it all, she did read 'will be shut down to prevent damage to windows'. Since then symptoms as described. Approx three month's ago similar problem occured, plugged monitor into onboard graphics socket instead of the plug-in card that it originally came with and it has worked fine since, until now. (The plug in graphics card was tested good in another system so suspected issue with socket (PCIe card). (Sorry I didn't mention before, forgot about that).
Press the power button now, fans spin up, dvd drive activates, but monitor doesn't switch on (no signal message), no beeps emitted. There is a speaker as it used to beep on start up.

I could be entirely offbase here but I have had a computer that did this once. It had a failed motherboard (due to a lightning strike, but I assume other types of total failures would cause this).

Unless someone with more expertise collaborates take that with a grain of salt but I still have that computer beside me as a reminder of why I have a UPS (the computer was off at the time and there was no storm, so it wasn't something I could have predicted, but still something I don't want to repeat).

Yes, I was trying to establish if the motherboard is at fault. With the information I provided I was hoping that other things could be discounted:

Do the voltages indicate the PSU is operating as it should. (readings taken with everything connected, so was under a certain amount of load).

Do the two readings from the code reader indicate the CPU has initiated the bios process and the failure is at this point and so indicates a problem with the bios chip and replacing this is required.

Or do they indicate the process hasn't got that far but they do indicate the CPU is active so the problem is very likely on the motherboard, in which case it would be more cost effective to get a new base unit. (The best price I've found for a new motherboard is £153- to get the same model, so my sister can use her existing HDD & Windows Vista.

The bios is Amibios and is the 8 pin soic type, so to swap that it would need soldering. (£15 for a programmed one). I don't want to start replacing that if, with the data I've got, eliminates the chip from the equation.

With everything removed apart from the CPU/fan and power supply there are no beeps, with ram added, no beeps and with monitor in on board graphics no display either.

I read a post from 2009 on this forum where Westom requested the PSU voltages as first step as this would give a lot of valuable data. From the information I've given can a Tech expert ascertain what point the boot process has reached and thus isolate the problem to a specific area. Eg The PSU is bad. Or if the PSU is good, it is definitely the motherboard failing, (esp. as the pcie slot won't recognise a known good graphics card- stopped working but on board graphics has been fine since for some three months). Or the PSU is good and with codes 01 F0 02 F8 the failure is at the bios because of checksum error. Or whatever it maybe.

Any advice would be much appreciated including an explanation of what the data does and doesn't mean.

Many thanks

Just to confirm, I have replaced the CMOS battery with a new one and have now also managed to test with a known working PSU and have tested the PSU in another system

The symptoms still persist but can definitely rule out the PSU. Do the test results from previous posts above indicate motherboard or BIOS or is thee a way to find out.

Thanks