There are many reasons why it does work, the main one, they put it together wrong. I have noticed with things I have bought a manual does not come with it, you download it from the companies site. So your neighbors need to read the info that came with the chair. A manual usually has a trouble shooting section. If they bought the chair from a durable equipment store, they may be able to help. Otherwise, they need to call the Manufacturer.
We can't possibly know why your neighbour's bath lift isn't working, that depends on the make, model, how old it is and their ability to follow instructions for it's use. Try contacting the manufacturer, the supplier or just searching the web with those parameters. I don't want to be unkind frank25184 but your profile says you are looking after a grandmother, to me that means should be young enough to be more internet savvy than asking the series of questions you have on a caregiving forum.
I don't want to be unkind frank25184 but your profile says you are looking after a grandmother, to me that means should be young enough to be more internet savvy than asking the series of questions you have on a caregiving forum.