Just a little heads up for some owners, I noticed that my ramp started to bind. It would raise just fine, but it would have a really hard time lowering. With the playfield raised, I was able to feel it bind, but I couldn't for the life of me figure out where it was binding. Anyway, just figured it out today, and it was the world's easiest fix. The armature on the left side was binding on the metal ramp guide--more specifically, the "knuckle" of the pin that extends into the ramp was grinding against the small horseshoe opening.
Looks like this is a factor driven by the aftermarket ramps, which are thicker, and don't line up perfectly. So the stargate ramp flap is pushed farther to the left, binding everything together. The simple fix: take a pair of pliers and gently bend the metal ramp guide left just a few millimeters. Good as new! Hope this helps someone down the road if they have a similar issue.