Jammed omni step

Hello forum members
Previously well working electric step on our 2008 Sigma failed to work when we went away this week. Step will not extend although we can hear the step motor trying to move it. We haven't knocked it accidentally, just working perfectly one day then not the next! Would be grateful for any advice before we take in in to be looked at.
Many thanks,
Liz

Thanks Peter,
We'll give it a go
Liz

Hello Peter,
Just an update on the step. My husband noticed a screw that had worked loose, allowing the step to retract too far and resulting on it getting stuck on a nut. He managed to remedy it using a rubber lump hammer and can of silicone spray. Seems to be working well now, fingers crossed. Many thanks for you advice.
Liz