I just put in a different power supply at the same time that I did the other upgrades. Power supply is old to me, new to this computer. 1000 watts of overkill (previous one was 430W so I thought maybe I was having power issues). So, power cable has been changed out. SATA cable also swapped out. Ugh, I guess I try a different cache drive? I'll try it because it makes sense as a next best troubleshooting step but I do think there's something else I'm doing wrong that's causing the problem. Thanks!