Wireless keyboard help, please

After months of problem-free use, my wireless keyboard has started behaving very strangely. When I try to pair it via Bluetooth with my computer (or any other), the two recognize each other. Then I get that window asking me to type a series of numbers into the keyboard and hit Enter. At this point I get a red-letter warning saying failed. I've restarted, unplugged, tryied three different computers and two different Bluetooth gadgets. So it's definitely the keyboard.

I have also tried putting in various sets of fresh batteries and run into the same problem.

Is the keyboard fried and time to get a new one? Or is there something I can do to resurrect it?

Thanks for any help!
Carl

 

Yes, I should have said that: it is an Apple wireless keyboard. I really think I've covered all the bases on the battery front. Tried different combos etc and I get the flashing and solid green light underneath.

I'll try this flashware thing you mention.

Thanks!
Carl