I have 2 furby,s & all I can tell you is if you have put new battery,s in .
And fallowed the insturctions to reset ( they must be all new battery,s (4 new). I say this because a furby for some reason take a bit of juice to start up. And one bad battery will drain the other 3.
If new battery,s and resetting has not worked you must operate on the furby .There are a few sites that explain how . They are all very simple to do. I was nervous to do mine due to the fact It was the first time I had ever handled mine. He had been in his packaging since 1998 .I had got another at a yard sale and wanted to see two interact.
I took my time and it took a total of 30-45 min taking my time from start to finish. So just take your time and be gentle the operation will be a success.