Something I always try to impress on junior team members is to not skip steps in troubleshooting. Even when you “know” it couldn’t be something, check it any-damn-way. Especially since if you’re troubleshooting correctly the first few things you try should be the simplest, most obvious and the quickest. To wit:

1) Is it plugged in?

2) Is it powered on/started?

3) Is there a DNS entry?

About half the time when my juniors can’t solve something, I come behind them and try the easy initial things it definitely “couldn’t” be and fix the issue.

Most people just do not have minds suited for troubleshooting I guess.