Stops sewing. just started about a week ago. Was sewing for about 2 hrs when it just stopped.

Question

just started about a week ago. Was sewing for about 2 hrs when it just stopped. pressed presser foot and just made humming sound. turned off and on several times. Would run few minutes then stop. Finally stopped. I turn it off and left it for 10-15 min. Then ran again. The next time I used it it did the same thing.