GXP 1620 Firmware Recovery Incomplete




I have a GXP1620 and it keeps getting the same “Recovery Incomplete” message after trying to update the firmware when turning on. Now guys, I’m not a tech savy and I’ve been trying really hard to read some related topics but I really can’t understand this thing of “option 66” or “tftp” so please, can anyone help me fix this issue? Because right now I can’t even access the admin page of my phone.



This error is damaged firmware.

TFTP guide:

Same program have DHCP which you also need run and set. DHCP option is part if this (see below).
Example setting DHCP option on your local network card in PC.
Pc have static IP 192.168.234
If you run on windows 10 TFTPD must be started with administrator privilege for saving settings.

Phone connected directly to PC port should auto restore firmware.

I hope this help, if not you will need someone with at least basic knowledge for PC/Network.


Apologies, but I’ve already downloaded this pDF and started following the step-by-step instructions, download the HFS and Firmware for the respective GS phone model, ran it but then when it comes to accessing the WEB GUI page, I input the IP form the HFS and it gets me to a page where the password admin/admin is invalid and I cannot access the web GUI for my phone. Then I can’t reboot it because it gets stuck in the same “Recovery Incomplete” page, I can’t download the FW either, I can’t access the webGUI…

This is getting on my nerves!


HFS is HTTP server not TFTP, you need TFTPD (start from 12 page).


Ok, I downloaded the instaled the TFTP64. ran it and completed the default gateway, mask, option 66, etc. Now it says on pg 16 that I must access the web GUI from the grandstream phone, which should be the IP address from the phone - which I cannot access because no matter how many times I reboot it, it gets back to the same page and won’t let you do anything else so I tried the ip that shows in the TFTP (which matched the one in the HFS) so I assume that it should be the ip for the phone, but when I get there it asks me for the username and password and it won’t accept admin/admin.

Ideas? Am I missing something?


I mean, how do I access the web GUI page if I don’t know my phone IP?


No need, Option 66 overwrite setting for upgrade.
PC <----> Phone
Phone ask IP from TFTPD and receive it with option 66 info where is stated ip firmware server.


Ok, I must be missing something.

I’ve downloaded the TFTP64. Installed it. Opened it. Adjusted the interface as shown in the PDF:

Then I’ve adjusted the settings as instructed:

Then what do I do next? Connect the phone to the desktop computer and reboot it? Click on something?

Please let me know,


Mark DHCP Server too.
You are not doing “normal” firmware upgrade.


Ok. Then what do I do? Connect the ethernet cable from the phone to the desktop computer and simply reboot the phone? Do I have to clieck anything else?


You should not.
In TFTPD log you should see IP getting from phone then later it should start downloading firmware.
You need down firewall or allow communication to TFTPD


I had similar issue with GXP1625 - connected to 3CX Server 16 when upgrading from to
The phone is showing “Firmware Update - Initializing”. This message will stay forever - if connected only to power cable (PSU). Upon connecting network cable after connecting power (after around 10 minute), the message will show “Firmware Update”, then “Recovery Incomplete
Note1 The phone will get IP from any DHCP Server, but option 66 of new DHCP is not overriding the config path / firmware path.
Note2 The phone is not responding to SSH or HTTP (GUI), or even to configuration through phone menu buttons.

The problem is that the Config path / Firmware path in Grandstream phone is pointing to 3CX / provisioning Server. We have to get that path (from other working phone). DHCP server option 66 is not overriding this.

  1. Power the phone using PSU power not PoE (no network)
  2. Assign a PC with same static IP as 3CX or provisioning Server
  3. Use DHCP sever in PC - to provide same range of IP as the provisioning server ( I am using TFTPD64 ). You may need to add Inbound rules to Windows Firewall
  4. Use HTTP Server. I am using HFS. You need to add exception in Anti Virus, or stop the Real Time Protection to run HFS (recognized as Malware) - You may need to add Inbound rules to Windows Firewall
  5. Set HTTP port in HFS to be same as in 3CX or provisioning server (in 3CX it is 5000)
  6. Add folders to HFS in same structure as the 3CX or provisioning server.
  7. Download latest Grandstream firmware update for that model GXP1625 - in my case, and unzip, and copy the .bin file in the folder (as requested by provisioning server) - inside HFS
  8. Connect network cable from PC to Grandstream phone.
  9. The phone will look for the updated firmware file in the same path as the provisioning server path and will start the update process, then reboot.
  10. Done