IBM 9348 Service Information page 21

Figure
1-2 (Page 4 of 4). Tape Read Reference Codes
--
Probable
Cause
I
Action Ref*
1
PartNurnber
Code
Operator
21 F7923
21 F7933
A test was run to read data from the tape, but no data was found.
Ensure that the tape has data by recording on it if necessary and
attempt the operation again.
This reference code can occur if the read or write cable is not cor-
rectly seated. Reseat the read and write cables and attempt the oper-
ation again to verify the repair. If this reference code continues to
occur, exchange the FRUs as needed. Attempt the operation again
after each FRU is exchanged to verify the repair.
Figure 1-3 (Page 1 of 6). Tape Write Reference Codes
Action
Ref.
Code
Probable
Cause
Part Number
A buffer underrun error occurred during a write operation. Run test 0.
If test
0
fails or if this reference code continues to occur, exchange the
FRUs as needed. Run test 0 after each FRU is exchanged to verify the
repair.
-- - -
A gap was detected before end of data during a write operation. This
problem may be caused by a bad tape or a dirty tape path. Clean the
tape path; see "Cleaning Procedure" on page 4-3. Load a tape that is
known to be good and attempt the operation again, or run test 0 to
verify the repair.
Tape
21 F7923
21 F7933
If this reference code continues to occur, exchange the FRUs as
needed, and run test 0 after each FRU is exchanged to verify the
repair.
Tape
21 F7933
21 F7923
- -
Three or more tracks were in error during a write operation. This
problem may be caused by a bad tape or a dirty tape path. Clean the
tape path; see "Cleaning Procedure" on page 4-3. Load a tape that is
known to be good and attempt the operation again, or run test 2 to
verify the repair.
If this reference code continues to occur, run test 98 to check the read
channel gain values. If these values are not good, run test 99 to set
new values and run test 2 to verify the repair.
If this reference code continues to occur, exchange the FRUs as
needed, and run test 2 after each FRU is exchanged to verify the
repair.
Tape
21 F7933
21 F7923
Two tracks were in error during a write operation. This problem may
be caused by a bad tape or a dirty tape path. Clean the tape path; see
"Cleaning Procedure" on page 4-3. Load a tape that is known to be
good and attempt the operation again, or run test 62 (with parameter A
set to 6) to verify the repair.
If this reference code continues to occur, run test 98 to check the read
channel gain values. If these values are not good, run test 99 to set
new values and run test 2 to verify the repair.
If this reference code continues to occur, exchange the FRUs as
needed, and run test 62 (with parameter A set to 6) after each FRU is
exchanged to verify the repair.
Chapter 1. Analyzing Problems
1-9