You can see the cable if you look down on the mechanism, or up through the kidney grill. They often stick such that they won't open and some ptfe lubricant on the mechanism sorts it
Whatever you do don't use WD40. After a few weeks it will start to harden and form a gooey paste that will thicken and bind with dirt and eventaully clog up the cable.
If its stuck up use WD40 for reliever, what I do even on my topdowns, any joints, noisy rubbing panels and hinges, I make sure they are always lubricated. I only use WURTH HHS2000, its a silicon grease, just spray after cleaning. This is very very very effective
follow this link http://www.wuerth.co.th/homepage_en/product/product_HHS.html