Archer C4000, v.3.6 (purchased 9/29 from Costco). I had a C8 AC1750 for several years that was dead silent, until it went dead. The C4000 makes this repeating low buzzing sound that lasts 4-5 seconds,

Have cable and router is between cable box and Win 10 desktop computer. Used iPad for a couple of hours earlier today, came back an hour later and couldn't get iPad connection to router. Here's what I