I am not able to update/upload modem firmware or application firmware.

[rwslaugh]

Im following the guidance to upload modem code and application code, downloaded from project page, onto the Thingy:91.

Current state, after following guidance, is: I hold down SW4 on power up, windows system recognizes a device, the nRF Connect (v3.4.1) - Programmer has a device to select. This device is listed as '0.01' - Serial port: COM11. Only a single serial port.

filename for modem firmware: mfwnrf9160120.zip.

The application I would like to load is the thingy91_Item_2020-04-29_bc7ade8b.hex.

It appears that possibly the bootloader is corrupted?

[Martin Lesund]

Hi Ryan,

Please confirm that when holding down the SW4 you also have the "SWD select" to "nRF52", or else you may have have overwritten the mcuboot in the nRF9160.

It sounds like the mcuboot has been overwritten /and/or corrupted. 

To confirm this please use the debug out port on the nRF9160DK or and external Jlink/programmer and use the 10-pin connector and program the full precompiled .hex  to the Thingy so it gets the MCUBOOT. 

That would be the way to go forward.

[rwslaugh]

Sorry for the delay. I agree you are right. I will look to use the debug or jlink.

[Martin Lesund]

Perfect. 
Let me know how it goes.