How to recover my new Thingy91?

[ReggieMax]

After unpacking I followed the first step at nordicsemi.com/thingy91, which is to update the firmware. I followed the linked instructions to update the modem and application via USB using freshly-downloaded desktop nRF Connect v3.3.3 tools and the files from the latest package (modem: mfwnrf9160120, application: ...\Thingy91\thingy91_fw_2020-04-29_bc7ade8b\images_full\thingy91_ltem_2020-04-29_bc7ade8b.hex) as recommended in a month-old thread "No connection to network after update - No LED indication"
I have the same result/problem as the original poster in that thread, but the responses there have not helped and I have not gotten any responses to my follow up question.

The first sign of trouble is that the modem fw update instructions state at the end of that page that AT+CGMR can be used to check the update. However, when using nRF Connect v3.3.3 - LTE Link Monitor all AT commands time out (again, my screen looks the same as the OP's in that thread).

The second sign of trouble is that I can find no clarity on which application file should be loaded to provide the same functionality as out of the box, or at least allow me to proceed with the Getting Started instructions for registering my device and connecting to the nRF cloud. (The contents.txt file does not answer this question.)

What should be my next attempt?

[Martin Lesund]

Hi Reggie,

Could you verify that you followed the instructions in the documentation?

• Programming modem firmware.
• Programming Application.

In the CONTENT.txt file in the .zip you have a description on which file to use depending on how you flash them:

Package contents:
images_full/          Full firmware images, updated over debug probe / development kit
images_dfu_hex/       Application images, updated over USB, HEX format
images_dfu_bin/       Application images, updated over USB, binary format

and you also have the description of the different files:

File                                                                              Description
--------------------------------------------------------------------------------  ------------------------------------------------------------------------
images_dfu_bin/debug/thingy91_ltem_dfu_debug_2020-04-29_bc7ade8b.bin              DEBUG Asset tracker firmware for nRF9160, LTE-M network mode
images_dfu_bin/debug/thingy91_nbiot_dfu_debug_2020-04-29_bc7ade8b.bin             DEBUG Asset tracker firmware for nRF9160, NB-IoT network mode
images_dfu_bin/debug/thingy91_nbiot_legacy_pco_dfu_debug_2020-04-29_bc7ade8b.bin  Asset tracker firmware for nRF9160, NB-IoT network mode, legacy PCO mode
images_dfu_bin/thingy91_at_client_dfu_2020-04-29_bc7ade8b.bin                     Firmware for direct modem communication
images_dfu_bin/thingy91_ltem_dfu_2020-04-29_bc7ade8b.bin                          Asset tracker firmware for nRF9160, LTE-M network mode
images_dfu_bin/thingy91_nbiot_dfu_2020-04-29_bc7ade8b.bin                         Asset tracker firmware for nRF9160, NB-IoT network mode
images_dfu_bin/thingy91_nbiot_legacy_pco_dfu_2020-04-29_bc7ade8b.bin              Asset tracker firmware for nRF9160, NB-IoT network mode, legacy PCO mode
images_dfu_bin/thingy91_nrf52_connectivity_bridge_dfu_2020-04-29_bc7ade8b.bin     Connectivity bridge for the nrf52
images_dfu_bin/thingy91_nrf52_usb_uart_bridge_dfu_2020-04-29_bc7ade8b.bin         USB-UART bridge for nRF52840 (deprecated)
images_dfu_hex/debug/thingy91_ltem_dfu_debug_2020-04-29_bc7ade8b.hex              DEBUG Asset tracker firmware for nRF9160, LTE-M network mode
images_dfu_hex/debug/thingy91_nbiot_dfu_debug_2020-04-29_bc7ade8b.hex             DEBUG Asset tracker firmware for nRF9160, NB-IoT network mode
images_dfu_hex/debug/thingy91_nbiot_legacy_pco_dfu_debug_2020-04-29_bc7ade8b.hex  Asset tracker firmware for nRF9160, NB-IoT network mode, legacy PCO mode
images_dfu_hex/thingy91_at_client_dfu_2020-04-29_bc7ade8b.hex                     Firmware for direct modem communication
images_dfu_hex/thingy91_ltem_dfu_2020-04-29_bc7ade8b.hex                          Asset tracker firmware for nRF9160, LTE-M network mode
images_dfu_hex/thingy91_nbiot_dfu_2020-04-29_bc7ade8b.hex                         Asset tracker firmware for nRF9160, NB-IoT network mode
images_dfu_hex/thingy91_nbiot_legacy_pco_dfu_2020-04-29_bc7ade8b.hex              Asset tracker firmware for nRF9160, NB-IoT network mode, legacy PCO mode
images_dfu_hex/thingy91_nrf52_connectivity_bridge_dfu_2020-04-29_bc7ade8b.hex     Connectivity bridge for the nrf52
images_dfu_hex/thingy91_nrf52_usb_uart_bridge_dfu_2020-04-29_bc7ade8b.hex         USB-UART bridge for nRF52840 (deprecated)
images_full/debug/thingy91_ltem_debug_2020-04-29_bc7ade8b.hex                     DEBUG Asset tracker firmware for nRF9160, LTE-M network mode
images_full/debug/thingy91_nbiot_debug_2020-04-29_bc7ade8b_debug.hex              DEBUG Asset tracker firmware for nRF9160, NB-IoT network mode
images_full/debug/thingy91_nbiot_legacy_pco_debug_2020-04-29_bc7ade8b.hex         Asset tracker firmware for nRF9160, NB-IoT network mode, legacy PCO mode
images_full/thingy91_at_client_2020-04-29_bc7ade8b.hex                            Firmware for direct modem communication
images_full/thingy91_ltem_2020-04-29_bc7ade8b.hex                                 Asset tracker firmware for nRF9160, LTE-M network mode
images_full/thingy91_nbiot_2020-04-29_bc7ade8b.hex                                Asset tracker firmware for nRF9160, NB-IoT network mode
images_full/thingy91_nbiot_legacy_pco_2020-04-29_bc7ade8b.hex                     Asset tracker firmware for nRF9160, NB-IoT network mode, legacy PCO mode
images_full/thingy91_nrf52_connectivity_bridge_2020-04-29_bc7ade8b.hex            Connectivity bridge for the nrf52
images_full/thingy91_nrf52_usb_uart_bridge_2020-04-29_bc7ade8b.hex                USB-UART bridge for nRF52840 (deprecated)
mfwnrf9160120.zip                                                                 Modem firmware, updated through nRF Connect for Desktop

For the "out of the box" application, it's the Asset_tracker sample. 
So you would need to select the version that suits which network technology you are going to connect to.
e.g. for LTE-M you select

thingy91_ltem_dfu_2020-04-29_bc7ade8b.hex                          Asset tracker firmware for nRF9160, LTE-M network mode

BR,
martin l.