BugZero | F5 BugID 526708 - system_check shows fan=good on removed PSU of 4000...

F5 - Defect ID: 526708

system_check shows fan=good on removed PSU of 4000 platform

F5 - Defect ID: 526708

system_check shows fan=good on removed PSU of 4000 platform

Last updated on July 18th, 2026

BugZero Risk Score
6.9 Medium

Overall: 6.9

Severity: 7.3

Community: 4.2

Lifecycle: 8.3

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Bug Details

Priority: 3-Major
Status: Verified
Impact Category: TMOS

Description

Symptoms

Running system_check on a 4000 platform with one PSU removed will still show status FAN=good; STATUS=good

Impact

Fan shows status of 'good' when the PSU is removed. Reading the power supply status in the system_check output will show the PSU as down.

Conditions

This applies only to the BIG-IP 4000 platform.

Workaround

None

Fix Information

If a PSU has been removed, system_check will now show status STATUS=not present

Change history

Links

Original Vendor Announcement

Relevant Products

Click on a version to see all relevant bugs

Affected versions:11.5.4, 11.5.4 hf1, 11.5.4 hf2, 11.5.4 hf3, 11.5.4 hf4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10, 11.6.1, 11.6.1 hf1, 11.6.1 hf2, 11.6.2, 11.6.2 hf1, 11.6.3, 11.6.3.1, 11.6.3.2, 11.6.3.3, 11.6.3.4, 11.6.4, 11.6.5, 11.6.5.1, 11.6.5.2, 11.6.5.3, 12.0.0, 12.0.0 hf1, 12.0.0 hf2, 12.0.0 hf3, 12.0.0 hf4, 12.1.0, 12.1.0 hf1, 12.1.0 hf2, 13.0.0, 13.0.0 hf1, 13.0.0 hf2, 13.0.0 hf3, 13.0.1, 13.1.0, 13.1.0.1, 13.1.0.2, 13.1.0.3, 13.1.0.4, 13.1.0.5, 13.1.0.6, 13.1.0.7, 13.1.0.8, 13.1.1, 13.1.1.2, 13.1.1.3, 13.1.1.4, 13.1.1.5, 13.1.3, 13.1.3.1, 13.1.3.2, 13.1.3.3, 13.1.3.4, 13.1.3.5, 13.1.3.6, 13.1.4, 13.1.4.1, 13.1.5, 13.1.5.1

Fixed versions: 12.1.1

Relevant Products

Click on a version to see all relevant bugs

Fixed versions: 12.1.1

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F5 - Defect ID: 526708

system_check shows fan=good on removed PSU of 4000 platform

F5 - Defect ID: 526708

system_check shows fan=good on removed PSU of 4000 platform

Last updated on July 18th, 2026

BugZero Risk Score6.9 Medium

Bug Details

Symptoms

Impact

Conditions

Workaround

Fix Information

Links

Top F5 Defects

Ready to prevent the next vendor outage?

F5 - Defect ID: 526708

system_check shows fan=good on removed PSU of 4000 platform

F5 - Defect ID: 526708

system_check shows fan=good on removed PSU of 4000 platform

Last updated on July 18th, 2026

BugZero Risk Score6.9 Medium

Bug Details

Symptoms

Impact

Conditions

Workaround

Fix Information

Links

Top F5 Defects

Ready to prevent the next vendor outage?

BugZero Risk Score
6.9 Medium

BugZero Risk Score
6.9 Medium