SIM868 firmware flashed but GNSS not working

Hi All
I am trying to flash a SIM868 module in order to restore the GNSS part, as it was totally missing when I got the chip.
I am using the MTK Flash Tool v5.1612 as in the image1 , and flashing by the UART connection.
The SIM868 is on a breakout card as in the image3.
This card include the connections between the GNSS serial port and the SIM UART2.

The firmware flash configuration (.cfg file) is:
ARM_BL (SIM868M32_BOOTLOADER_V005_MT6261_1418B03SIM868M32.bin)
ARM_EXT_BL (EXT_BOOTLOADER)
PRIMARY_MAUI (ROM)
VIVA (VIVA)
GPS (B03V02SIM868_11.bin)

The flash operation seems to be OK up until the GPS part.
At that point the flash tool seems to hang for 2 minutes and then reports that download has failed.
The module actually seems to be working, except the GNSS functions.
I can activate the GNSS module, but when I issue AT+CGNSINF I only get:
+CGNSINF: 0,,,,,,,,,,,,,,,,,,,,
The module has an external antenna, so the GPS signal is there.

My question is: what is the correct way to flash the firmware including the GNSS part?
Do I need a special hardware to achieve this?

Thank you in advance for help!

Looking at command response. Firmware is ok. You might be Indoors. Take device out for satellite sync to get values.

Hi Ravi
Thank you for reply.
I will try again to get outdoor signal and get back to you.

Please, help. How did you update firmware on sim868?

I have the same problem here. I’ve updated firmware and get +CGNSINF: 0,,,,,,,,,,,,,,,,,,,, right on my window.
Have you coped this problem?

Hi zhekaus
Our problem was electrical problem.
The module was mounted on a dev board purchased from not quality vendor.
We discovered that all the SIM868 hidden pads under the module were NOT soldered!
We managed to resolder the SIM868 to the card and the module worked.
So, at least from the flashing procedure available on the web, the FW flash is OK.
Hope this helps
Alberto