I don't see any dark spots, other than the blue paint pen marks ...
If you can't get to the backside of those to test, just remove one at a time, and check for power where they plug in, that will tell you if you have power to the fuse block, if you don't, then you have probably either a mouse problem, or a chaffing/pinched/cut wire situation, but either could also blow a fuse ...
If you have a multimeter ... Set it to check continuity and test like shown holding both leads together, then between both blades/pins of the removed fuse, if you have a solid ".000 like this, your fuse is good, it could show a little resistance like .005 and still be good.
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But if it shows 1.0 like this, when both leads are separate, then fuse is not good.
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