Hotpoint WD420 won't do final spin?

I wonder if anyone could help ?
I have a Hotpoint WD420 washer/dryer which won't do the final spin. It washes ok but at the final spin it seems to be going into the spin but then stops and just churns for a while and then repeats. It's as if rinse-hold had been selected but it hasn't.
I've checked the filter in the black bellows-like hose and found a penny and a woodscrew but even after putting things back together, the washer still won't do a fast spin. All lights look normal. The waste pipe isn't blocked.
When the programme is cancelled, the washer drains ok but the clothes are still quite wet of course.
Many thanks for any advice you can offer.