EHS36 with Plantronics Savi720 on T38G

[stscc]

We just purchased 4 T38G IP-phones with EHS36 adaptors to connect Plantronics Savi 720 headsets. We can't get the headsets to work properly. Depending on the setting of the switch on the base of headset incoming callers hear me but I don't hear them or the other way round. If I put the switch in position "C", everything works, I can pick up incoming calls from the headset, the icon on the phone indicates a connected headset, but the microphone of the headset is dead.
Plantronics support stated position "A" would be correct, but I doubt that, since in this position the headsets don't work at all. They didn't want to make any comments on the EHS36 since it is a third-party product.
Any ideas anyone...?
Can I perform a firmware upgrade on the EHS36 using the T38G phones? I only found firmware files for use with the T26/T28 phones. How can I determine the firmware version of the EHS36?

[Yealink Support]

Hi Stefan,
Please try to upgrade EHS36 firmware with below firmware on T38:
ftp://yealinkftp:yealinkftp@ftp.yealink.....0.162.rom

How to upgrade EHS36:

1.Upgrade T38G to the firmware 38.70.0.162:

ftp://yealinkftp:yealinkftp@ftp.yealink.....0.162.rom

2.Set a DSS key as Zero-sp-Touch

3.Press DSS key, it will prompt “Update Expand”, then press OK button, and it will prompt "Please insert expansion!"

4.Connect EHS36 to T38G, then it will ask connect it again.

5.And it will wait some time(please wait patiently, during this, please don’t reconnect it again.)

6.When upgrade finished, it will display "Update Success!"

If the problem is still, i am afraid we need logs to analyze the problem, and we just tested with Plantronics Savi 740, but didn't test with Savi 720, so we are not sure whether it works or not.
Could you provide PCAP trace, syslog(level 6) and config.bin these three file to us, so we can analyze?
Before you export the syslog, please set log level as 6, and reboot the phone, then click Start,and reproduce the issue, then click Stop,and export the trace, syslog, config,bin to us.
These three files are very important for us, hope you can kindly understand.
Thanks.

[tkisida]

Was this ever resolved? I have firmware 38.70.0.177 on the T38. I updated the EHS following the instructions above and update the Savi720 firmware. Depending on the ABCDEFG selector either the Mic or the headphone work, but not both at the same time on any setting.

[Yealink Support]

Hi tkisida,

Could you provide PCAP trace, syslog(level 6) and config.bin these three files to us, so we can analyze?
You can refer to the steps in the second post.