Jetson Nano won't boot because of start job

I created a service to run on boot on my Jetson, but hadn’t properly tested it. During boot, I get

A start job is running for my start job (5min 00s / no limit).

I’ve tried buttons putting the Nano into recovery mode and resetting it (separately), but the screen stays blank after I press them. Any tips?

If you mean you just went to recovery mode, then this will have no effect. Recovery mode puts the Nano in a custom device mode which a host PC understands with the driver package from JetPack/SDK Manager. Unless you flash the recovery mode will not change anything.

If you have this on SD card and know where the service is (such as a symbolic link in “/etc/systemd/system/” or a “*.wants/” subdirectory), then just mount this on a Linux host and rm the service file.