hi all, I have 2 headsets minix NT-1 for the kids to use on the iPad. All working fine until lately one of them is having an issue. I cannot find any manual to search for a solution..so hope someone over here can help me out. The pairing is done like normal, headset is charged but with intervals of approx 1 minute you hear 3 loud beeps and the led indicator is flashing in red. Any clue what's wrong ?