Electrician Dad and Son Try to Troubleshoot why a 480 Volt Circuit Breaker was Arcing, Thoughts?

Hey, so here's the problem. The problem is with this breaker here, he's telling me he's making snap, crackle, and pop sounds. >> Yeah. Says he has a breaker right above it that's a spare. Let's open up this side. This is a P4 panel. >> Yep. So, we got to take this cover off. Yep. This cover off so that we can get in and take this whole dead front off. Look at it. This is a three-phase, four-wire, and this this section is rated at 3,000 amps and it's fed with a 4,000 amp main. So, over here is a 4,000 amp rated You can see, Chris, that this is a section. Yep. This is rated at 4,000 amps. If we go over to this section, this section's rated at 2,500. We go to this section, it's rated at 3,000, 3,000, 2,500, and 2,500. Now, you can see that this was added. This is for the UPS. This one was added. I remember doing this one. Okay. So, let's uh let's start off. And you can see why you don't want to use a drill. These are all stripped out. Look at that. Yeah. That just literally came right out. So, >> Yeah, no. And I took one out right there. >> Oh, okay. So, let's let's remove these screws. All right. Here we go. Yep. Let's go. Let's start with this one. Put always put a hand on the panel. Never let go of it. Never let go of it? >> Yeah. Never let go. You have to always keep pressure on it cuz you don't know if these screws are ready to give or not, you Keep your hand on it. Yep. Keep your hand on it. Do the left side first and the right side or the >> matter. It doesn't matter? Yeah. Hold it.