FWIW, the reboots on my wr841nd appeared to be somehow related to the wifi. whether that's because of my crowded 2.4ghz neighborhood or something else i have no idea, but since i went out last week and picked up a few ubiquiti APs and turned off wireless on the 841, i haven't had a single reboot. i'm now at 8+ days uptime...so i was actually going on a day or two before disabling wireless, but i never had anything close to this with wireless enabled.
Router/Version: Netgear WNDR4500v2
Firmware: DD-WRT v3.0-r34311 (12/29/17)
Previous: r34080
Mode/Status: bricked/unresponsive
Reset: no
Issues/Errors: Installed new firmware, hoping to fix some minor wifi issues... After update, could not connect through ethernet cable at first, could not establish a connection (even though lights on the router turn on). Tried to do a hard reset by pressing the reset slot for more than a minute, but it does not respond, all the lights continue to flash as usual.
It was my second experience flashing router (after the first one it worked for a month), so it's possible that I messed up somewhere in the process...