Yeah, that side is more my speed, too. I built an arduino based compressor controller a few years ago when that went out. But this is something internal (high side pressure pegging the gauge 30 seconds after the compressor engages).

Took it by a friends shop to get it evacuated today and they agreed that my amateur assessment (dryer and expansion valve) was where they would start first. So I've got a bit more confidence going into it. Fingers and toes crossed I don't find a bunch of metal inside.