Possible leak from power vent in bathroom

Hello,

I have discovered twice water on the floor under the power vent in the bathroom. I have checked the inside of the vent and opened and closed it making sure it was closed and more water appeared.

I opened this vent for the 1st time last week.

Can I diagnose and repair from the inside? I'm disabled and ladders are off limits for me. I'm suspecting The repair must be done topside on the roof.

Thanks!

Dave