Sometimes you need to have the hand wheel off and check the gear behind there; it can be sluggish with dried up grease. Sometimes it can be anywhere on the machine, it once took me four days of oiling and test sewing to get a machine to run smoothly again.
If there isn't the slightest hum of motor or movement I would go through the wiring from end to end. Pedals can usually be sorted out, but if you have a second wroking pedal you could always try it.
Last edited by Mickey2; 04-09-2019 at 08:50 AM.