Recently found my old Boktai cartridge hidden away in my closet. I noticed the sensor doesn't really pick up on sunlight if it's through a window. Even with the window open I barely get 1 bar if at all. When I'm outside directly under a strong beam of light, the meter reads at just a bit over half. Is there some sort of maintenance I have to do to get the solar sensitivity up or is this what the game was always like?