Problem: Every vendor applies safety features differently; some features are proprietary and some of them are standardized. Similar to the OCP chip connected on each rail, over-voltage protection (OVP) chip is also connected on each rail. The OVP shuts down the PSU in the event that the DC outputs exceed a set level. Find out what is the minimum voltage levels required for compliance for the +12v rail, +5v rail and 3.3v rail. You might need an Internet to search for the answer.