2x Dell Vostro 1550 & 3550 Keyboard Malfunction (out of the Blue)

Hi Guys thanks for reading this I hope you are all well.

This is an odd one so I will start from the Beginning. A friend of mine purchased a Dell 1550 (second hand) after I pronounced a clean bill of health for it, then when my friend replaced the hard drive in the 1550(a) the keyboard stopped working, on the HDD was a pre-installed version of Elementary OS.

The Mouse pad works just not the keyboard. Simple I thought, when replacing the HDD he must have not put back the keyboard ribbon, or so I thought.

It was in there properly, so I thought it must be the OS but it won't boot into the BIOS settings (F2 or temp boot F12).

Fortunately I got my hands on another Dell 1550 (as this is a good friend who I owe a favour), I then Replace the keyboard from 1550a with 1550b, and it does not work!
I then try putting the keyboard which I switched BACK to 1550b and that Stopped Working?
So not only did 1550a not accept the new keyboard it seems to have stuffed it up some how.

I then search the forums and Try removing the battery, power cord and holding the on button for 30 seconds but still to no avail. (on all of them), I also removed the battery for a few hours and tried again but still the keyboard would not work!

Now. I got another Dell, a dell vostro 3550 and got its keyboard (very similar except with a back light, out it into Dell 1550b and it did not work in 1550b or 1550a, I put it back into the 3550 and only the back light (which was not plugged in) works. This was running windows 8 (and you cant go into the bios).

This has stummped me, does anyone have any thoughts?