Extensa 5630EZ doesn't POST

I realise there's already a few threads about this sort of thing, but I can't find any about this laptop and I'm still struggling to get it to work.

I've had the laptop about 18 months, it came with Vista, and an option to buy a Windows 7 upgrade disc, which I took. I can't think of any problems at all I've had with this laptop, until the other day, when Windows Update prompted me to install some new updates, I did and let the laptop reboot, but it never did. Now, when I press the power button, the fan starts, there's a flicker from the hard drive activity light, and the dvd drive makes a noise like it's checking for a disc, then nothing. The fan turns off after a few seconds (although I think that's normal), and nothing ever appears on the screen, I've tried an external monitor and there's nothing on there either.

After a lot of googling, I discovered the Emergency Bios recovery, and even though I hadn't done anything to the bios, the symptoms matched other people, so I thought I'd give it a go.
I downloaded the latest bios from the Acer site and used the WinCrisis program to format a usb stick and put the correct bios on it (renaming it to bios.wph). If I hold down fn+esc, then nothing at all seems to happen, there's a flash from the usb stick when I turn the power on, then it remains unlit, if I press any other key combination, or press no keys at all, then the stick lights up, but remains lit and doesn't flash to suggest it's being accessed.

I've tried two different usb sticks (both 1GB, FAT formatted), but most guides recommend a USB floppy drive, but the bios I've downloaded is 2MB, so I don't see how I can use that on this laptop.

I've tried putting the bios on a cd as well, but again, nothing seems to happen.

Is there anything else I can try, or is this starting to look like another issue?

 

Replace the bios battery. Seriously. Worked on three 5630's that would not post with a battery voltage of 2.9v or lower.

 

Thanks I will try that.
Stupid question, what should I expect to see if I removed the bios battery altogether?

 

Exactly what you see now- nothing. That's why Jay_d recommended buying a new COMS battery- that has worked in the past and even if it doesn't it's a cheap way of eliminating one variable.

 

No luck with a new battery, I'm assuming I'm close to needing a new board, but they don't seem to be too easy to get hold of.