IBM FlashSystem 900, Service Manual

Page: 275 / 546

3746-900 MAPs
MAP 5140: 3746-900 CP2 or CP3 Tripped
Symptom Explanation Conditions That Could Cause This Symptom
CP2 or CP3 tripped
-48v missing
¹
Overload on -48v
¹
CS/DCDC
¹
FANS
¹
SPD1 or basic board
¹
Any processor or coupler
001
An overload is mainly due to a board or cabling
malfunction. All the processor cassettes or CS
DC/DCs are protected by an individual fuse. The
fuse is located inside of each of those elements
and prevents a general -48v overload. These
fuses are non-replaceable.
Locate the tripping CP and its corresponding
circuit in Figure 2-5 on page 2-16.
Is CP2 tripped?
Yes No
002
CP3 tripped
Go to Step 007.
003
Unplug the DCDP connector J5 and reset CP2.
Is CP2 tripping again ?
Yes No
004
The overload is on the CS or fans.
Using Figure 2-6 on page 2-18 locate the
CP2-protected circuit.
Disconnect the J1 connector on the
CS/DCDC and reset CP2.
Is CP2 tripping again?
Yes No
005
Exchange the CS/DCDC. Go to
“3746-900 Maintenance Using a FRU
list” on page 1-28.
006
Locate the failing fans by disconnecting the
J2 connector alternatively on them one at
time.
007
The overload is on the basic board or in its SPD1
cassette.
Pull the corresponding SPD1 cassette out and
reset the CP.
(Step 007 continues)
007 (continued)
Is the CP tripping again ?
Yes No
008
The problem is on the board distribution.
Reseat the SPD1 cassette
Unplug all the processors and couplers con-
nected on the board and reset the CP.
Is the CP tripping again ?
Yes No
009
Reinstall all the processors and cou-
plers one at a time until the failing
part is isolated.
010
The board is failing. Exchange it. Go to
“3746-900 Maintenance Using a FRU list”
on page 1-28.
011
The problem is in the cable between the DCDP
connector J4 and the SPD1 cassette connector
J11 or SPD1 cassette. Check with a meter on the
test points. The CP may also be failing.
Chapter 2. MAPs for FRU Isolation
2-17