I’m familiar with the Power Gear version, but in general there is a switch under the bed that senses that the slide is fully extended. There are a lot of posts and work arounds on
www.irv2.com. But we’ve found that a first step is to bump the bed platform up towards the head of the bed from the foot. Sometimes this push’s the limit switch enough that the bed will operate.
The other fixes and work around consist of removing the mattress so you can lift the bed base and reach up to the top left corner to adjust the contact switch or remove the two yellow wires at the switch and connect them to bypass the switch.
The bumping with your knees has always worked for me.