I updated my jetson with Jetpack 4.5 by updating the sources.list file. It installed and asked for a reboot. It now simply keeps showing a full screen white background Nvidia logo that blinks off and on. I see no boot info or anything.
There is no update from you for a period, assuming this is not an issue any more.
Hence we are closing this topic. If need further support, please open a new one.
Please enable the serial console and dump the log for us to check.