You need a new Motor control board
You can order one from fitnessrepairparts. Com or Treadmill doctor. Com
O I'm not sure. Wmt will need to see if they have your exact model
Being that old it may be more cost effective to look into a new machine. Treads usually last about 8-10 years
If you can find one under 300$ I would maybe do it but I would not invest a ton
Please rate my answer, thanks!