Spectralink 7202 dect doesn't switch on

Hello, i have a Spectralink dect model 7202 and, basically, it doesn't switch on anymore. I push the power button but it doesn't switch on.

I tried changing the battery but nothing happens.

Maybe it crashed but i tried to open it and everything seems ok.

Is there something that i can check like volts or something?

Thanks,

Massimo