Default Factory reset not solved issue

I have 2 Yarvik TAB275EUK GOTAB ION 7" tablets. One won't boot up, it sticks on the loading screen. I have done a factory reset more than once, and the problem hasn't been solved. The manufacturer hasn't got any firmware downloads for the TAB275.

Is there any way of restoring the faulty tablet from the working one?

Any help appreciated.