Thanks so much for the reply!
Last night I tried doing the qdl method. I followed all of the steps and when I run qdl I get the following message:
Waiting for EDL device
It will wait in that state indefinitely. This is kind of what I expected as the dragonboard doesn’t enumerate when connected via USB.
This morning I bought a TTL to USB lead and connected to the UART on the dragonboard. If I boot with S6 set to 0000 I get loads of normal, sensible looking output. If I boot to SD (0100) I get the output below. If I boot to USB (1000) I get no output at all! That must mean the USB side of things is knackered right? I reckon I’ve maybe got the USBOTG stuff in a bit of a twist and caused some kind of short. Does that sound plausible? I did get some kind over-current warning when I first connected the dragonboard to my Windows PC so that could be a clue! I didn’t make make a note of the exact warning unfortunately. I really don’t know much about the USB side of things though (I will do some homework as soon as I can).
Below is my output when booting into SD Card mode (I think this is the interesting stuff I can include the logs before this as well if that will help). Does this give any clues as to why it won’t boot to SD? What would I have to know/read to get an understanding of this output?
Android Bootloader - UART_DM Initialized!!!
[0] [0] BUILD_VERSION=
[0] [0] BUILD_DATE=16:23:05 - Nov 5 2020
[0] [0] welcome to lk
[10] [10] platform_init()
[10] [10] target_init()
[40] [40] SDHC Running in HS200 mode
[50] [50] Done initialization of the card
[60] [60] pm8x41_get_is_cold_boot: cold boot
[60] [60] Rescue image for dragonboard 410c, boot into fastboot mode only
[440] [440] Not able to search the panel:
[480] [480] Config MIPI_VIDEO_PANEL.
[500] [500] Panel CMD: command mode dma test failed
[500] [500] dsi panel init error
[500] [500] Turn off MIPI_VIDEO_PANEL.
[600] [600] Not able to search the panel:
[670] [670] Config MIPI_VIDEO_PANEL.
[900] [900] Panel CMD: command mode dma test failed
[900] [900] dsi panel init error
[910] [910] Turn off MIPI_VIDEO_PANEL.
[1000] [1000] Not able to search the panel:
[1000] [1000] Unknown panel
[1000] [1000] Target panel init not found!
[1010] [1010] pm8x41_get_is_cold_boot: cold boot