Sun Microsystems 220R manual About Power-On Self-Test POST Diagnostics

About Power-On Self-Test (POST) Diagnostics

The POST diagnostic code resides in flash PROM on the main logic board. It runs whenever the system is turned on or when a system reset is issued. POST tests the following system components:

■CPU modules

■Memory modules

■NVRAM

■Main logic board

POST reports its test results via LEDs located on the system keyboard and on the system front panel. See “Error Indications” on page 138 for more information about LEDs and error messages.

By default POST displays detailed diagnostic and error messages on a local terminal, if one is attached to the system’s serial port A. For information about running POST, see “How to Use POST Diagnostics” on page 121.

120 Sun Enterprise 220R Server Owner’s Guide • October 1999