meirman wrote:
Here it is:
___ ___ ___
|___| |__| like this, except smaller segments, 2 or 3mm. Not
even in a critical spot, afaict. It's the lead from a resistor, it
looks like, that comes from an AC 12v transformer connection, to one
of the 4 diodes in a bridge rectifier setup.**

I agree with the idea that in this case, it's a fuse.

In high-speed logic circuits, sometimes you see "meanders" like this to
even out the trace length for two signals that should get there at the
same time, or should have a path with about the same capacitance or
resistance. They are typically much smaller than your example... maybe
1 mm or less spacing between the loops. You can see this easily on most
recent computer motherboards... follow the bus lines from the expansion
card slots, memory slots, or north bridge and see. I have even seen
these on some expansion cards, like Firewire and fast Ethernet cards. I
am told that fancy board layout packages will insert these for you
automagically.

Matt Roberds