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Bypass the router and plug directly into the computer. If it works, then your router may have lightning rot. A nearby lightning strike could have started it on the road to quitting.
You mentioned resetting it. Make sure you hold the reset button until the power light is flashing. 8-10 seconds generally.
fwiw, I tell folks 3 or 4 times a week that their Linksys has died. They are simply not as good as they were just couple years ago. Might try a Netgear nest time.