Motion Mc F5 startup problem

Hi you guys!

I am using the Mc F5 model in my work and I love it!

But last week the startup of the computer began to behave strange. I can't start it with the battery present, neither with a fully charged battery or with the AC adapter plugged in. The only way it starts is when I take out the battery and plug in the AC. Then I can put the battery back again and everything works fine. Hoewer it is a big problem for me not being able to start the computer without AC plugged in when I am working in the forest. I have tried two different batterys.

Any suggestions?

Thank you!