Preview Tool

Cisco Bug: CSCvs88749 - Loud buzzing noise when pressing speaker/Class-D Amplifier Damage Issue

Last Modified

May 26, 2020

Products (1)

  • Cisco Unified Communications Manager (CallManager)

Known Affected Releases


Description (partial)

Phone is not even on a call , just when pressing speaker generates a very loud noise
It makes the speaker unusable
Not all 7811 running12.6(1) experience the issue
On some phones issue might go away itself 
Rolling back to previous load does not fix it 
Factory reset does not fix it either

This issue is due to permanent damage to Class-D amplifier, thus causing issue with the speaker.

Impacted phone models:
7811, 7821, 7841, 7861

Upgraded  7811 to 12.6(1)
Bug details contain sensitive information and therefore require a account to be viewed.

Bug Details Include

  • Full Description (including symptoms, conditions and workarounds)
  • Status
  • Severity
  • Known Fixed Releases
  • Related Community Discussions
  • Number of Related Support Cases
Bug information is viewable for customers and partners who have a service contract. Registered users can view up to 200 bugs per month without a service contract.