Electric Hoist (Panshanger AL7)

Silverline 500W Electric Hoist 250kg.
Not working but motor is good and someone with sufficient knowledge might be able to fix it.
This hoist has been used for some years for moving light loads in and out of the loft. The 12m cable has never been extended more that 4 metres.
It always worked perfectly until the steel cable recently got into a bit of a loose tangle and managed to overstretch the spring retaining the down limit sensor (see photo 3). Up and down controls would not work properly afterwards. I managed to make it rewind cable by pressing 'UP' button while applying gentle load. 'DOWN' button did nothing. I suspect that it needs a reset of components that control direction of rotation.
I have bought an almost identical replacement which interestingly does not have the same down limit sensor mechanism.