7.6 How to Use OpenBoot Diagnostics(OBDiag)
When you turn on the system power,OBDiag runs automatically if any of the
following conditions apply:
The diag-switch? OpenBoot PROM variable is set to true.
Youhold down the keyboard’s Stop and D keys as you power on the system. The
systems’s ok prompt will appear.
In the event of an automatic system reset, POST diagnostics run under the following
condition:
The OpenBoot PROM variable diag-switch? is set to true.
Youcan also run OBDiag in an interactive mode and select which tests you want to
perform. The following procedure describes how to run OBDiag interactively from
the system ok prompt.

7.6.1 What to Do

Note - Perform this procedure with the power on and the keyswitch in the
Power-On/Off position.
1. With the keyswitch in the Power-On/Off position, press the Break key on your
alphanumeric terminal keyboard, or enter the Stop-a sequence on a Sun
keyboard.
Toenter the Stop-a sequence, press the Stop key and the a key simultaneously.
The ok prompt is displayed.
2. (Optional) Select a diagnostic level.
Three different levels of diagnostic testing are available for OBDiag; see Section
7.7 “How to Set the Diagnostic Level for POST and OBDiag” on page205.
3. At the ok prompt type:
ok setenv diag-switch? true
diag-switch? = true
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