IBM iSeries 270 Service Manual page 577

Do not use this procedure on FC 503x, FC 5076 and FC 5077 SPD migrated towers. For those towers,
use the "Power on/off the system and logical partitions" on page 561 procedure.
Do not use this procedure for FC 504x towers. If you are powering off a FC 504x tower, then power off
the system unit. Go to "Power on/off the system and logical partitions" on page 561.
Attention: If there is an SPD migrated tower on the HSL loop with this tower, then follow this procedure
very carefully. This procedure will help you determine if the SPD migrated tower is the next tower (leading
link) or the previous tower (trailing link) from this tower on the loop. Powering down a tower when the next
tower or the previous tower on the loop is an SPD migrated tower will cause a machine check that will
crash the entire system.
Note: If the system has logical partitions, then all operations on the console refer to the console of the
logical partition in which you are working.
Note: To locate a secondary partition's console, see iSeries
.
Perform the following with the assistance of the customer:
1. Determine if a tower on the HSL OptiConnect Loop is configured as a switchable tower. To determine
this either ask the customer or refer to Service Reference Procedures in the iSeries Service
Functions
information.
Is the tower configured as a switchable tower?
Yes: Continue with the next step.
v
No: The expansion tower or unit is privately owned by this system. Go to step 8 (See page 566).
v
2. Determine if the system which controls the SPCN for this tower also owns the tower's HSL I/O
bridge resource. To determine this, refer to Service Reference Procedures in the iSeries Service
Functions
information.
Is the tower's SPCN controlling system the same as the tower's HSL I/O bridge owner?
v No: Continue with the next step.
v Yes: Go to step 6 (See page 566).
3. Is the tower's SPCN controlling system already IPL'd and running OS/400
Yes: Continue with the next step.
v
No: You cannot power off the tower at this time. The SPCN controlling system must be running
v
OS/400 or at SST/DST to power off the tower. Correct that problem first, then perform this
procedure again.
This ends the procedure.
4. Work with the customer to switch ownership of the tower's HSL I/O bridge resource to the tower's
SPCN controlling system. To do this use the OptiConnect for OS/400 information.
Were you able to switch ownership of the tower's HSL I/O bridge resource to the tower's SPCN
controlling system using the OptiConnect for OS/400 information?
v No: Continue with the next step.
(TM)
Service Functions
(R)
or DST?
Analyze hardware problems
565