axle on Singer motor? won't turn?

Hi there,
I have a singer samba 6. Sewing became very slow, then stopped - I can't turn the hand wheel, extremely tight. I've cleaned out all the lint from around the bobbin by removing the panel underneath and the bobbin casing. I've taken teh end panel off, the belt looks fine to me. When I removed it off the small axle which I presume is the motor the wheel then turned beautifully by hand. I plugged the machine on whilst belt off and the axle on the black bit (?motor) just seemed to be making a huge effort but didn't turn.

My question is has the motor gone? Is this anything to do with the foot pedal.

IF I do need to replace the machine is there a make which you can recommend to a basic curtains/clothes sewer?

Thankyou all for helping. Rachel.