iMX7 Solo boot failure

I have bought 10pcs of Colibri iMX7 Solo 256MB | V1.1A and I found a problem with random boot failure. I use viola carrier board. The problem is that sometimes module do not boot up. If the module do not boot I see no output from u-boot, it’s look like u-boot not started or stayed before something send to terminal.

Do you see that behavior on all modules or only on some? How often do they not boot? Does power cycle help to get them booting?

I have tested only 5 modules, and boot problem arise on all, but difference was in frequency of failure. I made test with repeated boot via reset input pin. Of those 5 modules the problem occurred on all modules after up to 30 times reboots.

When modules do not boot the next reset help them booting.

The Colibri iMX7 have been assembled with pre-series silicon version of the SoC (PCIMX7S5EVM08SA) until V1.1A. Beginning with V1.1B, the modules will bee assembled with the new silicon version (MCIMX7S5EVM08SC) of the NXP i.MX 7.

We have seen booting issues on some of the pre-series modules of the iMX7D and iMX7S (V1.1A and older). The modules did not boot at a certain temperature range. At higher and lower temperatures, the modules have been working without an issue. Pressing the reset button, always recovered the modules. According to our investigations, it is an issue in the boot ROM. On the Colibri iMX7D with newer silicon version (Colibri iMX7D V1.1B) we have not seen the issue. So, the issue should be resolved in the series production version of the module.

All modules have to pass our production test before sending them to our customer. Since this boot issue is not permanent, it is possible that some of the modules with this issue have passed our test. Unfortunately, the new version of the Colibri iMX7S is still not available since it took a while until we got the new SoC version from NXP. Currently the new module version is in production. Since we did not want to make customer wait longer for the sample modules, the first products that are stated as “sample version” have been shipped with the old SoC version.

Ah cool, good to know. That explains a lot. I had that on every ~20th boot-up.