When you turn on the HMC, it performs a series of tests to check the operation of the HMC components and some optional devices in the HMC. This series of tests is called the power-on self test -- POST.

POST generates beep codes and messages to indicate successful test completion or the detection of a problem.

If a power-on password is set, you must type the password and press Enter, when prompted, for POST to run.

POST beep codes and error codes

A beep code is a combination of short or long beeps or a series of short beeps that are separated by pauses. A beep code indicates that POST has detected a problem.

You can also receive an error message rather than a beep code.

A single problem may cause more than one error message. When this occurs, correct the cause of the first error message. The other error messagse usually will not occur the next time POST runs.

For information about beep codes and error codes, refer to the Service Guide for Deskside and Rack-mounted Consoles manual.