Control board (replaced 4 years ago) doesn't light up. Unplugging and replugging the machine worked a couple of times. Now I have to trip the circuit breaker, wait a few minutes, and turn it back. Then the dryer usually works, although not necessarily on every setting. Last time, knit/low heat wouldn't turn on, but air/no heat setting worked. After the machine started running, I turned it off and quickly pressed knit/delicate. Then it worked. Usually, once I get it going, it will keep working for a number of loads, especially if I do them in rapid succession. Occasionally, it quits in mid-cycle. What is going on? It wouldn't be worthwhile to put a lot of money into fixing such an old machine, but if there's an easy fix, I'd love to know about it.

Update:

I pressed on the part that fits into a slot inside the door, and the light in the dryer did not go off. Does that indicate what part needs to be replaced?