IBM System 9000 Troubleshooting And Servicing page 24

II
!Test Faulty CRU
0 1
Planar board
02 Planar board
03
Planar board
Remove memory board and repeat test 4 .
0 4
I f retest passes , replace memory board .
I f retest fails , replace p l anar board.
05 Planar board
06 Defect ive p l anar board or defective MMU board ( if so equipped) .
Observe the yel low LED on the MMU board through the opening
in the processor unit back p l ate .
yel low LED is on , replace the MMU interface assembly and the
p lanar board .
board and the MMU interface assembly . I f the LED is f l ashing ,
replace the p l anar board, the MMU board, and the MMU interfac
assemb l y .
Remove memory board and repeat test 7 .
0 7
I f retest passes , replace memory board .
I f retest f ai l s , replace p l anar board.
08 Planar board
09
Planar board
Planar board
OA
OB Planar board
QC Planar board
OD Planar board
OE Planar board
OF Planar board
1 0 Planar board
1 1
Planar board
1 2
Planar board
1 4
P l anar board
1 8
Refer to Section 2 . 1 0 , "Printer/Plotter Problems"
for isolation of printer faults .
Remove sensor I / O board and repeat test 30 .
30
I f retest passes , replace memory board.
If retest fai ls , replace p lanar board.
9 7
Planar board
Refer to Section 2 . 7 , "CRT Display Problems"
9 8
to isolat e the fault to the p l anar
board or to the CRT display unit .
Automatic Diagnostic Tests - - Faulty CRUs
Tab l e 1 .
If the yel low LED
Return the processor unit to IBM for repair .
See Figure 5 - 1 . I f the
is
off, rep l ace the MMU
Fault Detect ion 2 - 9