ROCK 3A Product Defect Notice [Batch 2022-04-22/2022-06-15]

ROCK 3A Product Defect Notice

Last week, we found a serious defect in some recently manufactured ROCK 3A. Below is the problem description and our solutions for this issue.

Problem Description

In order to mitigate the part shortage, the key parts of all our products have more than one source, and ROCK 3A is no exception.The IP2315 and CH224D are two possible charge IC solutions for ROCK 3A (please check the last page in https://dl.radxa.com/rock3/docs/hw/3a/rock3a_v1.3_sch.pdf). This accident happened between those two parts.

Image 1: Schematic for Charge IC

IP2315 and CH224D are not pin-compatible, and requires different peripheral circuits to properly function. We have thus prepared 2 BOM for each solution.

In one production run, IP2315 was unavailable, and our inventory manager thought that IP2315 and CH224D could be interchanged. So he used CH224D instead of IP2315 and did not inform the ERP administrator to issue a new SKU Q2 BOM. During the production run, the manufacturing factory did notraise any question when there was a mismatch between the BOM and received parts, and they went throught all production stages and shipped the product. When using with the 5V adapter, all production tests were passed, so we did not notice any problem either.

The result of using the wrong BOM for production was that the charge IC CH224D is not working at all, and no voltage higher than 5V can be negotiated by the board.

The most direct effect to the user is that the system is more prone to reboot, or fail to boot when ROCK 3A is under high power consumption (high CPU load, some high powered SSDs, or many peripherals were attached).

Affected Batches

This issue affects all ROCK 3A manufactured between 2022-04-22 and 2022-06-15. The manufacture date can be found on the outer packaging.

Image 2: Manufacture date on the outer packaging

Solutions

For ROCK 3A users who have purchased the affected products, we offer three solutions to remedy the situation:

  1. Free IP2315 IC for DIY users to self-repair
  2. Replace / refund the affected board through our distributor
  3. Free power adapter to provide the required power for those ROCK 3A

We custom ordered a batch of 12V/2A USB-C power adapters from our supplier in very short notice. These special power adapters output 12V only without negotiation, and can support the high load operation of all peripherals connected to ROCK 3A. We will provide the matching adapter plug for the different countries.

Reflections

After the discovery of this accident, we review the situation carefully to find solutions and prevent such issue from happening again:

  1. We have added an ADC voltage test case that requires a voltage greater than 9V to be detected for it to pass the factory testing.
  2. Production must follow the BOM strictly, and for any change in a material the ERP administrator must be nitified to to provide a new and correct BOM.
  3. The factory has been informed that If there is a mismatch between the BOM and the parts, they must check with our engineers.

Conclusion

Radxa is an open source hardware team with many years of design and production experience. We are very sorry for a basic mistake like that using the wrong BOM for production which is not consistent with the high production quality that we often emphasize.

The accident did happen in a variety of coincidences and lead to a very bad user experience. Radxa team would like to extend our sincerest apologies to our users.

Looking back, we had some hints about this issue from our users, that when they used the QC adapter, only have 5V voltage could come out. But we thought they were isolated compatibility issue switch different brands of adapters, and didn’t take them seriously. If we paid more attention to those feedbacks, we might noticed this issue earlier. Radxa team would like to thanks, and apologize again to those users who provided the early feedback.

Radxa

2022/07/30

Appendix:How to replace CH224D with IP2315

This is for advanced user with SMD soldering experience only. We have marked the location of both charge ICs in the picture blow. With a hot air gun you need to remove CH224D and solder IP2315 at the following locations for PD negotiation to function:

Image 3: Locations for CH224D and IP2315

Make sure you have the correct chip orientation before soldering.

You can also reference ROCK 3A component reference file here: https://dl.radxa.com/rock3/docs/hw/3a/rock3a_v1.3_reference.pdf

CH224D is located at U28, and IP2315 is located at U27.

1 Like

How do we go about getting a replacement board? I just recieved my 3A today with 6/15 date.

这属于,测试不严谨,物料测试没有全部测试到位

Ah well, mine is dated 19-01-22, I feed it at fixed 12V from a DC-DC 24V-12V 3A, and for now I have not had any problems. Instead at 5V I had problems when I removed the wifi module and inserted a 4G module, when the SIM connection started, Rock-3A restarted, with 12V I no longer get this problem.
I believe 5V is only recommended for bare board users.

I will be careful for future purchases, as I want to use the Rock-3A for my series production, once the experimentation is over.