Found this on his patreon page. I'm not sure how old this is, and if this is the reason he's not been seen. But it was out there..
"Hello this is Mike of Mikes Radio Repair. Any support I can get will greatly help me in my goal of doing a complete electronics course on YouTube.
I will be cutting my work load in half to make time to do this course so I am going to loose a lot of income in this endeavor. Any support will help to finance the course, materials and supplies I will need create this course. The course will be free for anyone who wants to take it so your support will be helping out others to."
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