E-7023 is one of those errors I wouldn’t keep experimenting with, especially if the player is stuck on the error screen after a failed firmware update.
I’d check the firmware/update procedure and recovery options first, and if the player still won’t boot normally, it may need service.
There’s a dedicated section for the CDJ-2000NXS2 in the Save My Gig Field Manual with practical information on firmware, errors and troubleshooting:
https://www.savemygig.com/knowledge/pioneer-dj/cdj-2000nxs2
Antonio