Sun Microsystems Enterprise 250 Owner's Manual page 249

Note – By default, OBDiag output is displayed on the local system console or
terminal. If your server has been reconfigured to display output on an RSC console,
OBDiag results will not display locally. To redirect OBDiag diagnostic and error
messages to the local console, you must modify the OpenBoot PROM variables
input-device and output-device from the RSC console. See the Remote System
Control (RSC) User's Guide for additional details.
What to Do
Note – Perform this procedure with the power on and the keyswitch in the
Power-on position ( ).
1. With the keyswitch in the Power-on position ( ), press the Break key on your
alphanumeric terminal's keyboard, or enter the Stop-a sequence on a Sun
keyboard.
To enter the Stop-a sequence, press the Stop key and the a key simultaneously.
The ok prompt is displayed.
2. (Optional) Select a diagnostic level.
Four different levels of diagnostic testing are available for OBDiag; see "How to Set
the Diagnostic Level for POST and OBDiag" on page 234.
3. (Optional) Select a diagnostic target.
You can choose to run OBDiag with or without external loopback tests by using the
OpenBoot PROM variable diag-targets. For more information, see "OBDiag
Configuration Variables" on page 225.
4. Enter obdiag at the ok prompt:
ok obdiag
Chapter 11 Diagnostics and Troubleshooting 231