Here's a discovery I made (after some degree of frustration)...:
While installing new overhead light bulbs I accidentally shorted one out and all of them failed...indicating a blown fuse.
My WFCO converter has a column of Red LED indicators which are supposed to indicate a failed fuse. My presumption was that since each fuse has an LED beside it.... that must be the fuse indicated. WRONG!
No schematic existed to determine WHICH fuse serves which appliance circuit.
The LED at the top of the column was illuminated, yet the fuse beside it tested good. I spent the afternoon searching for burned wires and/or failed switches/connections/etc..
After much time spent on this I started checking other fuses in the panel and discovered that another fuse ...down the board... was blown. Replacing it restored service to the overhead lighting.
In other words, the illuminated LED was NOT adjacent to the faulty fuse. FYI.