My troubleshooting technique:
Problems: 1. Adobe CS5.5 performance in High Sierra. 2. After installing a wireless mouse and USB wi-fi plug, my two CD drawers would open on cold boot.
Solution: "Google it". Somebody somewhere has had the problem and knows how to fix it.
More problematic was when my internet connection failed (new supplier) and the only way to contact the supplier was by, um, internet. The solution was to wait for three hours. I spend far too much time on the internet. I hardly knew what to do with myself...
Mac Pro dual-2.4 GHz, 10.13.6, 24 Gb RAM, 250 Gb Samsung EVO SSD/Velocity Solo PCIe card, 2x3Tb Seagate HD, 1x3Tb Hitachi HD, Dell 2408WFP; Canon PIXMA iX6550; CanoScan 8800F; MacBook Air 1.8 Ghz, 8 Gb RAM, 10.14.4, 256 Gb SSD; Vodafone Home Hub/BT Wi-Fi Extender.