Cisco ASA5508 and ASA5516 Security Appliances Might Fail Due to Faulty Resistors

Due to a manufacturing process issue, some Cisco ASA5508 and ASA5516 security appliances might have a damaged resistor component. The affected units were manufactured between 2017-05-18 and 2017-08-25.

Security appliances with a damaged resistor will function normally on installation and product failures are expected to increase over time beginning after the unit has been in operation for approximately 18 months. Once the security appliance has failed the unit will no longer function, will not boot, and is not recoverable.

A resistor often costs only a few pence (or cents for our US readers). We don’t often see this kind of issue with Cisco kit but it just proves that it can happen to the best of company’s.

Problem Symptom

The security appliance no longer functions and the system fails to boot. There will be no output from the console port.

In addition, the LED status indicators on the security appliance illuminate as follows:

  • Power LED is green
  • Status LED is amber and blinking

Cisco recommends proactive replacement for affected ASA5508 and ASA5516 security appliances. There is no workaround for this issue.

Customers should request replacements for affected product(s) via this link –

Jason Davies

UK based technology professional, with an interest in computer security and telecoms.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: