FAQ: MS390 Memory Failure

What is the issue?

Through it's quality monitoring of product returns, Cisco has discovered a small percentage of dynamic random-access memory modules (DRAMs) and dual in-line memory modules (DIMMs) from a specific component vendor, manufacturing lot, and date range may exhibit a higher rate of failure in certain products. We addressed this issue with the supplier, who has taken corrective action, and we continue to monitor field failure rates.  

Which Cisco Meraki products are affected by this issue?

Through continuous quality monitoring, Cisco subsequently identified that a limited number of DRAM and DIMM components in a small subset of Cisco Meraki MS390 switches are impacted by the faulty memory modules. Monitoring showed the rate of failure has increased beyond predicted failure rates, and a replacement strategy is now recommended.  

Please note, there are no Catalyst 9300-M switches impacted by this issue. 

Why are affected customers being notified now about this issue in the MS390 switches?

Based on field failure rate monitoring, the rate of failure has increased beyond predicted failure rates. For this reason, a replacement strategy is recommended. 

What action is Cisco taking to remediate this issue in the impacted MS390 switches?

Cisco is replacing customers’ affected devices.  

If you have affected devices(s) in your possession, you will receive direct outreach from a member of our Network Support team via a customer support case. 

Please note: DRAM memory modules are soldered onto the motherboard printed circuit board (PCB), therefore the memory modules on the MS390 switch are not field replaceable. The entire switch will need to be replaced if the DRAM memory is affected. 

Are all MS390 Product IDs (PIDs) affected by this issue?

No, only a subset. Please check whether you received an email from the Meraki Support team notifying you with affected serial numbers. 

What was the root cause of this issue?

The root cause was determined to be a manufacturing issue limited to a small subset of MS390 switches that contain defective memory modules. This issue can result in early field failures and degradation of the memory modules. The impact is specific and limited to certain date codes. 

What quantities of MS390s shipped were impacted?

Approximately 0.75% of MS390 switches shipped with affected DRAM. 

How does the issue present?

Excessive Single Bit Errors (SBEs) can lead to system crash and subsequent unrecoverable boot failure. Reload/IOS XE upgrade/power cycle of an affected switch can lead to unrecoverable boot failure. It is important to note that a DRAM degraded switch may not show any errors prior to failure. 

Are there any software fixes for this issue?

No. This issue is not software related. 

Are there any workarounds for this issue?

No. Avoid any IOS XE Upgrade/Reload/Power Cycle reloads, upgrades, and/or power off an affected switch until it is replaced. 

Can DRAM degradation on affected switches occur during normal operations?

Yes. Reloads, IOS XE upgrades, and/or power cycles may trigger the failure and should be avoided, if possible, until replacement units are available for installation. 

How long will it take for proactive replacement product(s) to arrive?

Replacements will generally arrive in approximately 10 days from request, apart from high-VAT countries which will encounter longer lead times and may require upwards of 40 days for receipt. Due to the proactive replacement nature of this program, service level objectives will not apply. 

How do I track the replacement request?

You will receive an email with your order number and tracking information once the RMA has been processed and shipped. 

Are delivery times variable by country?

Due to Trade Restrictions, some countries will have a longer lead time for order delivery. In general, the following countries will have a longer lead time: All LATAM countries, all non-EU EMEA (European Union) countries, all APAC countries (EXCEPT: Japan, Australia, New Zealand). 

Who can I contact if I have additional questions and/or need support regarding this issue?

If you have questions about this issue and have already been contacted by a member of our Support team, please work with them to address your concerns.  

If you have questions about this issue and have not already been contacted by a member of our Support team, please contact Meraki Technical Support.