【Problem Description】：
A server cannot be powered on, with the following error message recorded in the SEL.
【Problem Analysis】：
According to maintenance.log, the faulty circuit is CPU34_vmse.
According to the circuit diagram, the circuit is on the mainboard and provides power for CPUs 3 and 4
Replace the mainboard. If the problem persists, check CPUs 3 and 4.
【Solution Description】：
Check the mainboard first and then CPUs 3 and 4. If "CPU12_vmse" is displayed, check the mainboard first and then CPUs 1 and 2.
【Experience】：
The hddbkp_vcc error in maintenance.log is a false error.
To determine whether it is a false error, check the drive backplane type. The backplane at the customer site is an 8-bay backplane. If it is a 25-bay backplane, determine the cause of the error.
