[msommerfield]

So an update on this…

The board boots fine now, I think there was an issue with the power cable connector pin crimp but that seems to be a solid connection now so mechanical as root cause of not booting seemed correct.

It now seems to have migrated to an issue where it boots and runs fine for a couple of hours then completely shuts down.  Before it does, however, it send the following message over the debug port:

[ 6335.602430] musb-hdrc musb mdrc.1: VBUS_ERROR in a_wait_vise (88, <AValid, retry #3, port1 0003010c

At this point, it powers off and I need to power cycle the power supply and then it will reboot fine.

Can you help me understand what this means and what might be causing it?

Matt

[msommerfield]

So I have some updates to this issue.

We had the eMMC pulled from the board that died. I powered it up and same issue – the voltage LED flashes for a barely perceptible amount of time, then off. Then I pushed the reset button for a few seconds and when I released the button, it came to life! I put the SD card in and booted fine. This worked for a few cycles, then died again.

We had a second board experience similar issue. It was running great for many months, then no more. I set it aside, moved on to other working boards, then miraculously, it came alive again with no changes. It ran without issue for a few months, then died again. This time, I had the debug terminal logging and captured the following as it died:

[108176.172460] musb-hdrc musb-hdrc.1: VBUS_ERROR in a_wait_bcon (88, <AValid), retry #3, port1 0008010c

I did a power cycle, and the following happened:

U-Boot SPL 2019.04-dirty (Mar 10 2020 – 21:03:25 -0400)
Trying to boot from MMC2
Loading Environment from EXT4… OK

U-Boot 2019.04-dirty (Mar 10 2020 – 21:03:25 -0400)

CPU : AM335X-GP rev 2.1
I2C: ready
DRAM: 512 MiB

That’s it…..after a couple of power cycles, I got nothing again.

I hoping the final data dump helps provide some insight in what may be happening here. We have some in the field and more to ship and want to make sure we have a robust product.

Thanks for your help!

Matt

[msommerfield]

Neeraj,

Thanks for the prompt response!

The voltage select issue makes sense. Looks like a red herring to the second.

The dead board was 100% working for many months. No changes were made nor was it exposed to any potential shorts, errant connections, etc. between working and not. It won’t boot from SD or eMMC. I checked all the voltage lines and they are not shorted and the only output I get on any of the lines is visible with the LED on the 3.3 line for a barely perceptible amount of time. We have reviewed the power up procedures/guides and here are few factors that may be in play:

– we had trouble with random resets with just power on the 5 VIN line and found a forum that suggested we connect USB VIN and VIN to resolve. It did and those lines are connected in our setup.
– at the moment this board failed, it was powered from a laptop on the USB line AND a VIN source. We had many months like this with no issue, but maybe it caused one now. All the other boards (with much less use) have already been disconnected from the PC USB power to prevent being dual sourced.
– as our reference design started from a pocket beagle, we do not have the clamping circuit

Could an eMMC fail in a way that prevents the Octavo chip from coming up at all? I get nothing on the debug port in terms of data.

Hopefully this information can help us find the root cause.

Thanks!

Matt

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