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dtogkas
Staff
dtogkas
Staff
July 1, 2026

Troubleshooting Tip: False 'P1_VDDCR_CPU voltage out of range' event log on FortiGate-3500F with SMC firmware v1.05 or below

  • July 1, 2026
  • 0 replies
  • 111 views

Description

This article describes a false-positive voltage anomaly event that is logged on FortiGate-3500F units running an older SMC (System Management Controller) firmware revision. The alert reports the P1_VDDCR_CPU voltage as being at or above the upper non-critical threshold, even though the hardware is operating normally.

Scope

FortiGate-3500F with SMC firmware revision v1.05 and below.

Solution


On affected units, an event log similar to the following is generated:

action="ipmc-sensor-monitor" msg="P1_VDDCR_CPU voltage out of range: 1.30 volt (at or above upper non-critical threshold)" logdesc="Voltage anomaly" status="failure"


Reviewing the System Event Log (SEL) from the IPMI controller shows repeated upper non-critical voltage events on the same sensor:

diagnose hardware ipmitool sel elist

 1f1 | 05/20/2026 | 02:51:12 | Voltage P1_VDDCR_CPU | Upper Non-critical going high | Reading 1.30 > Threshold 1.30 Volts
 1f2 | 05/21/2026 | 09:54:10 | Voltage P1_VDDCR_CPU | Upper Non-critical going high | Reading 1.27 > Threshold 1.30 Volts
 1f3 | 05/21/2026 | 10:29:55 | Voltage P1_VDDCR_CPU | Upper Non-critical going high | Reading 1.30 > Threshold 1.30 Volts
 1f4 | 06/06/2026 | 02:14:53 | Voltage P1_VDDCR_CPU | Upper Non-critical going high | Reading 1.27 > Threshold 1.30 Volts
 1f5 | 06/06/2026 | 02:50:03 | Voltage P1_VDDCR_CPU | Upper Non-critical going high | Reading 1.30 > Threshold 1.30 Volts


These entries are the reason the alert is triggered. However, this is a false positive.


Root cause:


The issue is caused by the sensor thresholds defined in older SMC firmware, where the upper non-critical threshold for the P1_VDDCR_CPU rail was set too low. As a result, normal CPU voltage readings (for example 1.30 V) reach or marginally cross the configured threshold and are logged as a voltage anomaly, even though the actual voltage is within the safe operating range for the hardware. This can be seen in the SEL above, where readings at or even below the threshold value are still recorded as 'Upper Non-critical going high'.


Confirming the SMC firmware revision:


To verify whether the unit is affected, check the SMC firmware revision with the following command:

diagnose hardware ipmitool mc info


Review the Firmware Revision field in the output. If the SMC is running revision v1.05 or below, this false voltage alert is expected behavior.

Workaround / resolution:

Newer SMC firmware corrects the threshold values so the false alert is no longer generated. The SMC firmware cannot be upgraded by the customer or directly by TAC. Therefore, the resolution is to request an RMA for the affected device so the SMC can be updated.

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