GXP1780 CS510A APD 80 EHS not working Closed


GXP1780 (Last firmeware Plantronics headset CS510A, Plantronics EHS cable APD 80 EHS.
The pickup is working sometime ( I need to push many time the button on the headset), the hangup never.
When I push the button on the headset, I can ear a clic but nothing is done to manage the hangup or pickup
The compatibility is OK. I don’t know what to do.
First time I have a problem even after hundred installations!


Did you check :slight_smile:http://www.grandstream.com/sites/default/files/Resources/gxp21xx_17xx_headsetcompatibility.pdf
And did you also get the other interface cable as well?


Thanks for this information.
I see:
Plantronics Cable 85638-01 (formerly 40287-05) is used with Plantronics EHS cords such as Plantronics APC-42 EHS on some Cisco IP phone models where the headset port is located too far for the EHS to reach. It is ONLY needed if you need longer cord length for your EHS, such as if you have a Cisco expansion module sidecar.

It’s seems to be only to longer cord length .
I’ve check also with another firmware:, I’ve the same problem.

No cable use the EHS plug on the GXP1780.

On the plantronics web site I can see:

I don’t know what to do!
Best regards


I am a Plantronics reseller, and you need the cable that is pointed out. Please do a search of the forum and you will see others with the same issue and the resolution being the cable. You are showing a 2124 phone which is obsolete and does not have the same firmware loads.


Thanks a lot for your response.
I’ve receive a brand new CS510 for Poly but with same bad result.
I’ll check asap with 85638-01 cable and if its’ working well ask Poly to modify their document to have better feedback.
Brice Ferrandes AccesIP France


The US site is correct. I cannot say for the EMEA site.

You can look up the Grandstream headset compatibility guide (Google it) or when using the US site (at least) you can click on the “related notes/articles” where it will outline the need.

As I pointed out earlier, your post indicated the GXP2124 which is obsolete and not the same as the more current models and they did not require the cable, so, what you show is also correct for the 2124.


Dear Larry,
I’ve received from Plantronics (Poly) The Spare Cable Assy, Modular Straight P/N 85638-01 and i’ts working now.
I 'll ask Grandstream and Polycom to modify the compatibility list to add the F…G cable because it’s mandatory.
Now I can hook and hang up from the helmet remotely.
If you visit South Est of France please keep me in touch, I’ll be happy offer beer, wine or champagne.