Unable to Recover iMX7S

After an unsuccessful flash of an image to the iMX7S V1.1B, there is no U-Boot prompt anymore. So, I tried recovering the module using this doc. I put the module into recovery mode, and running ./update.sh -d was apparently successful, but there still isn’t any U-Boot prompt on the module after a reboot. Any help with this would be appreciated!

@JaredT: Have you actually run the commands listed under “4. On the target, use the following commands …” in the uboot? If you did, could you post results (text output)? I believe that running ./update.sh -d only brings up bootloader on device, but does not write anything into NAND at all.

@EGM That’s the thing, I can’t run the commands. After doing ./update.sh -d, no U-Boot prompt or anything else appears. It’s a totally blank screen.

@JaredT: Oh, thanks for clarifying that. Does the lsusb and ./update.sh -d output match what is written in knowledge base?

@EGM Yes, lsusb shows ... Freescale Semiconductor, Inc. and ./update.sh -d shows ... success, but still no U-Boot. It’s really odd because I didn’t get any error messages throughout the process.

How is your serial terminal connected? Did the serial terminal work before?

After successful download (e.g. download ending with jumping to 0x877ff400) U-Boot should definitely print something on the serial console.

I have an Iris carrier, so through the X13 connector. It did work before.

I tried using the latest release, 2.7.2, with a Colibri iMX7S, recovery seems to work here. I get the usual U-Boot console output right after ./update.sh -d.

U-Boot 2016.11-2.7.2+g60021a4 (Apr 10 2017 - 03:49:01 +0200)

CPU:   Freescale i.MX7S rev1.2 at 792MHz
...

Make sure to remove SD-card and RTC battery, unplug power from the board for some seconds and try to recover again…

Do you have a second module just to verify that your RS232/serial terminal setup is still ok?
Do you have a RS232 adapter with LEDs or some other means to see whether there is a activity on the console?

Tried it on a different computer and it works now. Seems like there was a problem with the old computer.