Black Screen/Unresponsive to BIOS flash

Hello, I wonder if anyone can help. At the moment I'm using a massive, slow, vista running pile of something unpleasant. I want to be using my One, but it's dead. It has bricked before a couple of times, but I've always managed to flash the BIOS and get it running again before now. This time, the power light won't flash, the USB stick shows no activity.

Any ideas? Before my poor One ends up under the back tyre of my car or in the sea off the coast of Dover.

 

So, I've read about draining the CMOS battery as a possible fix for this complete lockout. Concur?

If not, I would guess it's a dead HD. In which case, the replacement becomes uneconomical and the Acer dies. Then, a Dell Inspiron Mini will be replacing it.