To eliminate any problems with low batteries always have shore line plugged in when operating slides.
The slide switch can have a problem and the spring contacts do not return to normal.
In
QT's 1 & 2 you have slide operation links to explain, here is one about
the switch which is on page # 5 of old slide spec.
For people interested here is the
new slide spec.
This link will lead you to slide parts for replacement.