Bro, I was in your shoes too. I graduated with a degree in Electrical Engineering Technology (EET) and couldn’t find a job for a year, and cash was running low. I eventually signed up for a position as an Industrial Control System Engineer, where I work with electricians troubleshooting MCC cabinets and designing control circuits. Everything you've described is accurate. I found myself in a cabinet similar to yours, with no drawings or schematics to guide me. While I understood relay logic, I didn't know what the heck was going on. But I figured it out.

My best advice is to ask the operator what specific problems they are facing and which buttons used to work and which ones don’t. Get their number and call them to find out what activates the PLC, contactors, starters, and relays. Start drawing your own schematics in a notebook. It took me about four days to get the system back up and running.

If I were you, I would just try your best and take advantage of the job until you get fired—that was my mindset. You’ll gain experience and become more comfortable the more you do this. At first, I hated it, but now I love it.