Sennheiser SK 100 Bodypack Transmitter won't power...

Question

I have a SK 100 . I used it with noproblem Thurs. night and turned it off . Then went to perform Sun. mornand all I got when I put a new battery in it was the red on/low Batt light. Nothing happens when I press the red power button. Nothing appears on the screen. I tried several newalkaline batteries and one the rechargeable we use in our wireless handhelds. Any ideas why?