[YMCS/YDMP Free Trial Program]Yealink would like to offer Free Trial Program of Yealink device management service for our current eligible customers. You can see the details below.

Post Reply 
Thread Rating:
  • 0 Votes - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
T28P Handset Noise Problems
Author Message
temp0001 Offline
Junior Member

Posts: 16
Joined: Jan 2014
Reputation: 0
Post: #10
RE: T28P Handset Noise Problems
I came across this issue with one handset last week.
I found that when the curly cord is closer to other electrical wires, the hum/buzzing gets worse. I swapped the curly cord with a known good one, and the problem persisted, indicating the fault lies in the microphone.

As others have done, unplugging the handset for a period of time resolves the problem.

It seems that the electret condenser microphone in the Yealink handset can develop an over sensitivity to hum fields if left powered on for extended periods. The microphone is always powered - I discovered this by putting the headset up to my ear whilst holding down the hook switch with my other hand, I can still hear sidetone.

Maybe if an electrical bias develops on the microphone, causing an imbalance on the two microphone wires, makes it is more susceptible to picking up hum and interference. My theory is that disconnecting the handset allows the charge to dissipate in the dielectric of the condenser microphone, allowing it work normally again.

Maybe a potential fix (that the Yealink engineers can apply to new firmware) is to turn off the power supply to the microphone when the handset is on hook?
03-09-2014 12:01 PM
Find all posts by this user    like2    dislike0 Quote this message in a reply
Post Reply 

Messages In This Thread
T28P Handset Noise Problems - fdtcloud - 02-20-2014, 07:18 AM
RE: T28P Handset Noise Problems - fdtcloud - 02-21-2014, 12:08 AM
RE: T28P Handset Noise Problems - braymond - 02-27-2014, 10:58 AM
RE: T28P Handset Noise Problems - braymond - 03-04-2014, 09:49 PM
RE: T28P Handset Noise Problems - fdtcloud - 03-07-2014, 06:16 AM
RE: T28P Handset Noise Problems - temp0001 - 03-09-2014 12:01 PM
RE: T28P Handset Noise Problems - Walter - 06-18-2014, 09:18 PM
RE: T28P Handset Noise Problems - braymond - 06-19-2014, 07:50 AM
RE: T28P Handset Noise Problems - Walter - 06-20-2014, 06:43 PM
RE: T28P Handset Noise Problems - belcom - 01-03-2016, 10:11 AM
RE: T28P Handset Noise Problems - mbello - 08-23-2016, 10:59 PM
RE: T28P Handset Noise Problems - belcom - 08-24-2016, 06:30 AM

Possibly Related Threads...
Thread: Author Replies: Views: Last Post
  Weird noise when answering via speakerphone nestman 6 9,254 06-16-2021 03:05 AM
Last Post: nestman
  T28P foward call doesn´t work with Tato 4 4,890 09-14-2020 03:49 PM
Last Post: complex1
Lightbulb Yealink T28P Firmware Upgrade Fails Michelth 11 40,700 06-27-2020 10:13 AM
Last Post: complex1
  T28P LDAP Problem oguzhan 1 4,437 06-10-2020 01:14 PM
Last Post: beldimon
  T28P Ringtones V2.70 Starlifter 22 88,638 11-29-2016 01:47 PM
Last Post: Psilverwood
  SIP-T28P Can't Answer Multiple Incoming Calls Trutelecom 1 5,269 08-31-2016 05:10 AM
Last Post: Trutelecom
  T19 makes humming noise imon32red 1 4,032 08-24-2016 06:49 AM
Last Post: mbello
  No sound on SIP-T23P handset AjN3806 1 4,604 07-18-2016 01:12 PM
Last Post: AjN3806
  T28P firmware thankappas 1 4,924 04-27-2016 05:33 PM
Last Post: Karl_Yealink
  T28P Not Showing Voice Message Notifications anymore mazuno13 3 7,603 04-07-2016 02:59 AM
Last Post: mazuno13

Forum Jump:

User(s) browsing this thread: 1 Guest(s)

Contact Us   Yealink   Return to Top   Return to Content   Lite (Archive) Mode   RSS Syndication