You might want to download a book here. "How to Troubleshoot a TV Receiver" by Johnson. It is too big for me to make into an attachment.
https://worldradiohistory.com/BOOKSH...helf_RIder.htm
Look about half way down the page and on the right for a book with a blue cover. It has some good pictures and explanations of problems. It probably doesn't help that much at the moment but it may in the future. Published in 1953, so for a much later set it may not be accurate.