The purpose of this article is to discuss a Cisco Nexus Boot Issue and what you can do to resolve it. The problem happens when the CLI on the Cisco Nexus switches crashes and begins to write a bunch of white lines. Unfortunately, power cycling may not help fix the problem. You can try to fix the issue by going through various troubleshooting steps found within Cisco documentation: Cisco Nexus 9000 Series NX-OS Troubleshooting Guide, Release 6.x – Troubleshooting Installations, Upgrades, and Reboots [Cisco Nexus 9000 Series Switches] – Cisco.
If you have not done so yet, open a case with Cisco Support to get their help. Otherwise, you should contact the reseller or managed services provider you purchased them through.