Hum when using Wideband Handset on 53xx

[MitelInMyBlood]

We just rec'd a case (12) of new 5340s that have a label on the underside of the handset near the earpiece. Some users have noticed that these are causing a low freq hum esp. when the mouthpiece is held against their chin. Anyone else?

 

[IrwinMFletcher]

Nope, just tested it at my desk.

Here's something to try. Take a person that is complaining and have them try it on a phone of a person that isn't complaining.

If the person that was complaining doesn't hear it, swap the phones and see if it follows the phone. If they still don't hear it, take the 'good' phone back to the problem location and see if it's an environmental thing (sitting next to a fan etc).

I once troubleshot a problem with 'distorted/choppy audio'. Turned out they were standing next to a fan that happened to have the right frequency to interfere with the person's voice.

 

[MitelInMyBlood]

Definitely a handset problem.

I can replace the handset with a new one from maintenance inventory and the hum is gone. The problem handsets have a label on the underside just below the earpice. The label says "Wideband". After further investigation not all of the new phones are affected. Only those with the label. So far only 3.

On affected handsets the hum is loud and can easily be heard by anyone using the phone. Moving the suspect handset to another instrument, ie, a 5212, and the hum follows.

 

[IrwinMFletcher]

Before you writeoff the handset, keep in mind that it's the phone software load as well as the system loss plan that determines what is being send to the handset. The wideband handsets would most likely require a compatible release version, what version are you running? What version are the wideband handsets compatible with (I don't know)?

I have a system with 9.0UR1 and don't hear a hum (5340 with wideband handset), but that doesn't rule out a problem with a particular batch of them. To clarify, you're having problems with ALL of the wideband handsets, or just some of them?

 

[MitelInMyBlood]

So far probs only with 3 that have the silver "wideband" label under the earpiece. I've since opened all 12 of the sets in the case and only 3 show the symptom. This case of new instruments has been in our inventory about 9 months.

 

[IrwinMFletcher]

From what I understand all 5340's should have the wideband handsets, perhaps you have a pre-release shipment? It's odd that you have a mixture.

I take it that it's more noticeable with calls to tdm endpoints? or is it even noticeable as sidetone?

Either way, sounds like it's something that could be reported to Mitel support.