Hello,
I'm still uncertain which situation you are describing so, I may have 2 solutions for you.
1) If you are on SU3beta there is a bug in the last beta that cause emissive lights to bug. So you click a button, the button light doesn't change, but the button action is running fine. --> If it's that, you can't do anything beside sqitching view from inside to outside and inside again so taht the light is updated.
2) Your EMER BATT is not working and only that : That may be a maintenance you have to do. Go to EFB, Maintenance, and do the batteries maintenance.
Regards,