About a year ago my stove would fail while baking, the oven would be off and the clock would be 12:xx, as if there was a power bump xx minutes ago. Since we had not had a power bump, I opened the stove up to check the logic board. No loose connectors or anything obvious, so I checked out the price of a new one. The local shop wanted $300, so I checked the internet. Found one place at $200 and one at $100. The stove stopped failing, so I didn't buy one. Glad I didn't. Recently it started failing again, but now the clock was completely out. Fiddled with the stove and found a) the 115v outlet on top still worked OK; b) if I turned a burner on it wouldn't heat, but the clock would light up for a second. Experience (I'm a retired computer/electronics tech) told me this indicated I was losing one side of the 240v input. Could be the electrical panel circuit breaker, wall outlet, or power cord. A voltmeter showed I had 240v at the outlet, so the circuit breaker was OK. Went out and bought a wall outlet $5 and power cord $25. When I removed the old wall outlet the problem was obvious: in three holes (ground, neutral, one power) I could see two heavy contacts pressing together. The other power hole had no visible contacts, either they had lost spring tension or broken. Installed the new outlet and all OK. Returned the unused power cord.
I may not be able to troubleshoot nearly as fast as I used to, but eventually I get there.