I often and aggressively harp about NOT encouraging DIY (do-it-yourself) repairs. Depending on the equipment, I WILL wholeheartedly (and sometimes rudely) discourage such practice. This would include someone working in a skilled trade who attempts to expand their service (repair) endeavors.
Here's a video on Youtube of an older incident that still serves as an example as to WHY I do think this way:
My position holds true in reverse as well. If there's an issue with an electrical outlet or within an electrical distribution panel, I will ALWAYS refer a customer to a licensed electrician...which I am NOT. That's THEIR area of expertise.
DISCLAIMER: Despite my forty years of experience in troubleshooting electrical equipment, I've never had a reason to become licensed electrician. That's not a fallacy in my past trade practices. That's the nature of my personal experience. I'm R-E-A-L-L-Y good at troubleshooting electrical problems (patting my own back), but a license was simply never a requirement for the jobs I did.
I hope this helps. Questions/comments are welcomed.