T2XP Series Phones Experiencing Buzzing/Humming

[onellpadmin]

I have had two T26P phones experience the exact same issues in two different geographical locations within the last week.

They both suddenly started experiencing a buzzing sound that can be heard by both parties in the call. It sounds exactly like electrical interference and can sometimes be stopped by holding the phone in a specific way while making contact with another object in the office. Had to temporarily replace them with old Polycom's I had in storage, much to my dismay.

Troubleshooting included attempting new codecs including G.711 and G.729, attempting to operate the phone strictly through PoE instead of the power adapter, factory reset of phones, moving the phone to different locations and different ports/switches. Also tried swapping the handset cord and still experienced the same issue.

The buzz is not heard while on speakerphone or while using a wireless headset plugged into the headset port. It is only heard while using the provided handset. I would have to assume the problem is either in the phones base itself, or far more likely in the actually handset piece. Perhaps frayed wires or internal components have come loose in the handset thus causing electrical interference or an oversensitive microphone picking up on electrical humming from nearby components.

Would appreciate help and guidance on what to do next to solve this issue. Thank you.

---

Also attempted one more thing to confirm it is the handset piece. Took a working handset from another Yealink T46G phone, plugged it in to the T26P having issues, and the noise was gone. Plugged the handset that was in the T26P into the T46G, and the noise issues carried over. This confirms the problem is in the handset piece itself. Would like to hear any suggestions on how to fix and/or replace. Thank you.