AC68U is endlessly rebooting

The router is using John's Merlin fork V27E5. The router is seemingly in an endless boot cycle where the power LED will stay solid for about 20 seconds, then the LAN lights will flash, then the USB light, then back to power, and it repeats. I can't communicate with it.

Here's what I did:

1. I disabled WMM APSD to see how it helped with an unrelated issue, then rebooted the router.
2. When it came up, wireless and wired transfers would then dip to almost 0mbps every 5 seconds or...

AC68U is endlessly rebooting