So you don't get the rest of the output listed here where the test passes and initialization completes?
NetScreen NS-5XT Boot Loader Version 2.0.0 (Checksum: A1B6FF9B)
Copyright (c) 1997-2003 NetScreen Technologies, Inc.
Total physical memory: 64MB
Test - Pass
Initialization - Done
Hit any key to run loader
https://kb.juniper.net/InfoCenter/index?page=content&id=KB5519
It would seem there is a hardware failure in that case then.