Do not rub the mirrors fiercely to prevent damage of the coating on the mirrors.The cleaning frequency recommended is once every 1 – 2 weeks.
If wood and paper are used frequently, the lens and mirrors can get dirty faster. Clean them with a wet Q-tip. Alcohol can be applied if the stain is tough.
The focus lens is inside the lens holder which are located under the third reflecting mirror. Lower down the platform or remove it out of the machine to make room for later procedure. Rotate the lens holder ring clockwise to release and remove the lens holder.
▲ Release and remove the lens holder.
Rotate the silver ring on the lens holder counterclockwise to take out the focus lens. Use pliers if the ring is too tight to rotate.
When putting back the lens, the curved side should face up and the flat side should face down.