Chosen Solution
I purchased this exact model at a yard sale this past weekend. Similar issues. Any advice for someone who is not particularly experienced with electronics?
There’s loads of stuff in the Internet to enable you to learn about electronics, but it’s scattered about. That’s why we put together the Restart Wiki at https://rstrt.org/wiki where you’ll find a wide range of pages covering tools and techniques, basic electronics theory, and general principles of a range of electrical and electronic goods, all geared towards diagnosis and repair and assuming no prior knowledge but only a sense of curiosity and a willingness to learn. Something to dip into as and when you feel the need or inclination.