Sorry for suggesting you didn't try the on/off button, but you'd be surprised at how many folks wouldn't think of that!
However, the key board appears to have 'Hyper Blue LED indicators' which may in this case be none working for what ever reason.
I think you may have to ask a friendly repairer, whether it be a PC one or electrician to have a look and check it for you. Should they want to charge you, it may be cheaper to buy a new one.