Frozen evaporator coil (again)

This is the second time the evaporator on my refrigerated display case has frozen up like this. The first time a tech came and thawed it out and then said it froze up because the drain line was angled upward, not allowing it to drain properly? The tech happened to come during a power outage so his troubleshooting ability was somewhat limited at the time. The day I called the tech, the compressor fan would not kick on. I thought maybe the fan motor was dead. But after it was thawed out, I flipped the power back on and the fan kicked on again. So, I guess not… What are the possible causes and what can I do, as a skilled end user, to narrow things down or fix it? submitted by /u/No_Reality_7706 [link] [comments]