The Acorn 120 stairlift or superglide slimline model can be identified by their burgundy reddish color fabric upholstery on the seat. This model had a rack and pinion drive and a silver rail or track. The gear rack is on the face or top of the track and can easily be seen. Also the Acorn stair lift has one lever to swivel the seat manually. The 120 was redesigned around 2010 and replaced with the model 130.
Battery testing and replacement
Power supply and transformers
Blown electrical parts
On/Off Lift keys