GIGASET S850H doesn't turn on

So my wireless landline phone piece no longer turns on.

The only life indication I can see is that when you put the batteries in. the green button flashes once. Another is clicking the green button makes the red button flash once.

I’ve tried charging it, changing batteries, and connecting it to a computer.

I’ve also opened it up and by visually inspecting it I can see no bad components.

Anyone got any ideas?