I could not figure out how to get the power input fuse out (kind of hard to get at) so I marked the wires with tape …unscrewed the power inlet…took it out, then was able to check the fuse…seems ok. The marking smeared on the tape so not sure which is which on the left two (or does it matter? I know which is the top one
Top (middle) is ground. Upper left is neutral. Lower left is hot / load and is the fused connection. You want the hot to be fused for electrical safety, so you don’t want to swap hot and neutral. Trace the wires from the power supply. The hot is usually designated L, neutral N, and ground uses a ⏚ symbol, or occasionally G
For looking up more pictures and information with a web search: This is an IEC C14 socket