Can't access Apalis IMX6 recovery mode

Hi!
My Apalis IMX6 neither boot nor is able to be put into recovery mode anymore. The problem started after my last try to flash a new Linux-image to the device by

  1. entering recovery mode, as described here

  2. installing Toradex Easy Installer from host PC

  3. loading a new image via USB-stick.

This procedure has worked well for me several times before but now my board seems bricked.

If I try to boot it, only one LED (LED1, the one closest to the recovery pads) lights up solid green instead of the usual three (LED{10,4,1}) and I have no output on HDMI, e.g. screen goes into power saving mode.

If I try to put it in recovery mode by connecting it to my Ubuntu laptop using the X9 micro-USB connector and the recovery-linux.sh script I get the outpt “no matching USB device found”.
Neither “dmesg” nor “lsusb” show any new device when connected and powered on, so it seems to me as if the board is bricked, it is not found by my laptop.

Is there something else I can try? Is it maybe possible that I have a broken board due to improper shortage while trying to put the device into recovery mode, e.g. shorting cable touching other parts of the board? Any ideas on what else can have gone wrong?

I have searched but did not find anyone having the same issue, putting the device into recovery mode seems to always work but not for me…

HI @TheMicroManagementTourguide and Welcome to the Toradex Community!

If I try to boot it, only one LED (LED1, the one closest to the recovery pads) lights up solid green instead of the usual three (LED{10,4,1}) and I have no output on HDMI, e.g. screen goes into power saving mode.

It looks like your SoM is in recovery mode because something went wrong during the installation.

If I try to put it in recovery mode by connecting it to my Ubuntu laptop using the X9 micro-USB connector and the recovery-linux.sh

You need to turn off the carrier board, shorten the recovery pins on Jp4 and turn on the carrier board.

Did you remove the JP2 on the Ixora Carrier Board?
Could you check if you see a FreeScale device when you type lsusb on your host?

Best regards,
Jaski

Thank you for your time and reply!

You need to turn off the carrier board, shorten the recovery pins on Jp4 and turn on the carrier board.
I have tried this; if I restart my board, either by pressing the power button twice, reset button or removing and attach again the power cable and then pressing the power button, I still only get one green led, no HDMI output and no new USB-device on the host machine. I have tried both lsusb and dmesg to see if a FreeScale-device has been found by my host when connecting my board with no luck.

Did you remove the JP2 on the Ixora Carrier Board?
Yes.

Could you check if you see a FreeScale device when you type lsusb on your host?
I do not see a FreeScale device with lsusb when I connect my board to my host any more.

/T

I do not have that kind of tools available at the moment but I’ll see if I can get it and I will come back with the results.

Thanks

Thanks for your Input. We will wait for your feedback.

Best regards,
Jaski

Hi, I am sorry for the delay. I have now been able to measure the voltages of the test points. My results are shown below. Thank you for your patience!

Results:

+V3.3_AUDIO: +3.29V

+VREF: +0.747V

+V1.5_VDDIO_DDR: +1.498V

+V2.5_VDDHIGH: +2.5V

+V1.2_VDDSOC: +0.192V

PWR_CPU_RESET: +0.014V

PWRON: +0.43V

+V1.375_CORE: +1.370V

+V1.375_SOC: +1.374V

+V1.8: +1.799V

+V3.3: +3.24V

PWR_ONOFF: +0.025V

+V1.1_ARM: +0.385V

+V1.1_VDDPU: +0.292V

+V5_USB: +4.98V

+V3.0_RTC: +0.042V

+V3.3_MXM: +3.24V

+V2.8_VDDHIGH: +2.77V

+V2.5_ETH: +2.49V

+V1.2_ETH: +1.193V

Best Regards

Hi @TheMicroManagementTourguide
Thank you for the results. They are very interesting. The first rail that should get enabled is the +V3.0_RTC which is missing on your board. The SoC uses this rail for its power management. The SoC should output a high level at the PWRON which signalizes the PMIC to start ramping up the rails. This output is powered by the +V3.0_RTC rail. Therefore, it makes perfect sense that this value is not high in your case. However, strangely the PWRON is at 0.43V. It looks like this value is big enough for the PMIC to turn on all the rest of the rails. The rails that are missing are created by the SoC and missing since the CPU_RESET is also not released.

Either there is something broken in the PMIC that prevents it to generate the +V3.0_RTC or there is anything shorted on this rail. Do you have multiple modules with this issue? Was that module running before? Has anything happened to this module?

Hello,

Thank you for the explanation, it is indeed very strange behavior.

I have had similar behavior on two or three modules, all of them was working fine until they suddenly did not, I have however not measured the voltages on all those boards. They were all running our modified Linux image, the same image that still runs on another board just fine right now.

The only thing I can think of might have happened to the malfunctioning boards are if, after the recovery phase, when removing the metal pin I used to short the recovery pads with it have touched some other part of the board and thereby shorted something else.

Is there a way to do a more “hard reset” of the module, something that might let the PMIC reset?

Best Regards

Hi

Is there a way to do a more “hard reset” of the module, something that might let the PMIC reset?

I don’t think so.

Could you file up a RMA and mention link to this community?

Thanks and best regards,
Jaski

Hi @TheMicroManagementTourguide

By shorting the recovery pads, you short the SOC_BOOT_MODE0 with the +V3.0_RTC rail. Since the +V3.0_RTC is the rail that is missing, it could have been that you have shorte the +V3.0_RTC pad to something else. I kind of doubt that shorting the +V3.0_RTC to GND would kill the PMIC LDO for the +V3.0_RTC, but I have never tried that. Maybe it was a higher voltage or even ESD.

It would be interesting to know whether on the other modules also the +V3.0_RTC is missing. if so, it would be quite a coincidence if it broke the same way with ESD.

In the end, it is really hard to understand what really happened.