I have a Kenmore Heavy Duty 70 series dyer and I recently replaced the door switch actuator and the drum belt. Once both of those were replaced dryer starts just fine, heats up, and the drum is spinning as it should.

I noticed that when I put everything back together that when the door is shut and the timed dry is on any sort of minutes instead of just off, the timer is making a very small humming noise. I tried a few different scenarios:

- If the dryer door is open/not shut the whole way, no noise
- If the timer is not on any number, no noise
- If the time is on a number within the timed dry, it makes the slight hum noise

My questions are:

1. Could this be a loose connection that I might have hit when I leaned the top of the dryer back?

2. Is this dangerous if I leave it be? I don't want something to catch on fire if I can ignore the noise and just leave the dryer door open or the timed dry on zero if not using it.

3. What could I possibly do to check if it's a connection issue or the timer itself?