I realize many computer geeks have ADD (like I do) and love to hyperfocus on a problem. That's excellent. My stubborness has kept me working on problems that almost everyone else gives up on.
This doesn't apply at 3 AM. If you are paged to respond to a problem and you find it isn't a simple reboot or misconfiguration, STOP. Take notes. If you tore down a configuration or a machine to fix something, STOP.
Make a list, even in your head, of what you can triage to keep the problem from getting any worse. If that means you have to back out of the changes you did just to get to status quo ante, do it. Think in terms of, "I can restore AR in 20 minutes but the other machines will take longer. One of them I can't bring up now, so I'll just do the AR db and have to hold off on everything else."
And go home at 4 AM if need be. Or sleep.
You may have to tell the boss, "I came in, worked on it, the problem wasn't what I thought it was so I had to back out. Let me regroup for 20 minutes and see what I can find out."
Because it might not be on your end anyway. It might be something you need to hand off to networking, development or your vendor's tech support.
If you made a change and the change did not fix anything, ALWAYS back out of the change! I hate getting something working and then finding two dozen unrelated things I did that didn't fix it. If you need to make those changes after all, identify the original problem first!
Point is, I love solving problems and I love sticking with a problem and not letting it go until I have a resolution. But I hate deathmarches, 3 AM calls that extend to 8 PM and firefighting in general.