DS8000 Service Documentation Version 7.5

Exchange the DC-UPS DC supply unit (DSU)

Before you begin

CAUTION:

This assembly contains mechanical moving parts. Use care when servicing this assembly. (C025)

Icon for electrostatic discharge wrist strap Use approved ESD procedures to prevent damage.

Attention:

This is not a stand-alone procedure. Customer disruption and damage to the hardware might occur if microcode and power boundaries are not in the proper conditions for this service action.
If you were sent here by a serviceable event FRU repair, the microcode and power boundaries have already been set.
If you were not sent here by a serviceable event FRU repair, see MAP1230 Replace a FRU without using a serviceable event.

Notes:

All the cables and FRUs to be removed must be uniquely identified so they can be reinstalled correctly.
If an installed earthquake resistance kit prevents you from accessing this FRU, refer to MAP1600.

Remove the DC-UPS DC supply unit (DSU)

Procedure

Open the left rear cover. Remove the two screws that secure the right rear cover (trained service personnel access area only).
Open the right rear cover. See Figure 1.
Note: The screws must be reinstalled when the cover is closed to prevent customer access.

Figure 1. Removing retaining screws on right rear machine cover
To locate this FRU, do one of the following and then return here and continue to replace the FRU:
- If this FRU has a FRU identify indicator, use the FRU identify indicator, which is listed in MAP1240 Locating FRUs using identify indicators. If not, use the location code.
  Note: There might be cases where the FRU failure or fencing conditions prevent the FRU LED indicator from being lit even if the FRU has power.
- Use the location code, which is listed in MAP1245 Finding FRUs by using location codes.
- If there is no FRU identify indicator or location code, you were sent here by an isolation MAP or symbolic FRU procedure. Use the information in that procedure and the figures in this procedure to locate the proper part to exchange.
Figure 2. Base rack locations, front and rear
Most, but not all, FRUs have identify indicators. Use the flashing amber or solid blue FRU identify indicators to ensure that you are working on the correct enclosure or FRU.
Note: The DC-UPS DSU amber identify LED should be blinking. See Figure 10.
- The "light path" identify LEDs are a hierarchy of LEDs that can identify the rack, enclosure, FRU, and even the FRU connector to which a cable is connected.
- For more information, refer to MAP1240 Locating FRUs using identify indicators.
Remove the right rear cover. See Figure 3.
1. On the upper and lower door hinges, loosen the screw and pivot the retention plate that secures hinge pin .
2. Lift the hinge pins up to remove them.
3. Remove the rear cover and place it in a safe location.
4. Temporarily store the hinge pins in the rack or cover hinges.
Figure 3. Removing rear left cover (right rear cover similar)
Unfasten and then rotate all six power distribution units (PDUs) away from the rear of the rack. See Figure 4.
Figure 4. Power distribution units in normal position (rack rear view)
Use a PDU service tool to keep the upper three PDUs in the open position. Use a second PDU service tool to keep the lower three PDUs in the open position. See Figure 5 and Figure 6.
1. The PDU service brackets are stored in the Rack-1 front upper left documents enclosure.
2. The upper three and lower three PDUs swing out as separate groups. Each group of three has a removable PDU alignment bracket.
3. The PDU service tool should be installed at the bottom of the middle PDU of each group of three PDUs.
4. The PDU service tool bottom tab is inserted between the upper and lower PDUs.
5. The PDU service tool fingers and straddle the PDU support bracket.
6. Figure 6 shows the tool properly installed. The tool is delicate, do not put unnecessary force on the PDU group.
Figure 5. PDU service tool

Figure 6. PDU service tool installed
Before proceeding, carefully study how the various cables are routed and secured. At the end of this procedure, you need to restore the cable routing and securing to allow the PDUs to be fully closed. There is little room between the PDUs and the DC-UPS DSUs for the cables.
To complete this procedure, you might determine there are additional cables that you need to temporarily move out of the way to allow easy access. Remove and then later restore cable ties as needed.
Remove the upper and/or lower cable bracket as needed to allow access to the DC-UPS DSU upper and lower sections. See Figure 7. Remove the cable ties as needed. Loosen and do not remove the screws . Remove the bracket.
Figure 7. Cable bracket
If you are removing the upper DC-UPS DSU, remove the rear door latch bracket . It is held in place by two hex head screws . See Figure 8.
Figure 8. Rear door latch bracket
READ THIS ENTIRE STEP BEFORE PERFORMING IT.
1. Confirm the location of the DC-UPS DSU being repaired. The DSU Service LED is flashing.
2. Disconnect the cable from Ex-J9 at the bottom right of the OTHER DC-UPS DSU - the one NOT being repaired. See Figure 9.
3. With the J9 cable disconnected, the DSU Service LED is now out on the DC-UPS being repaired.
Note: This protects the DC-UPS DSU not being repaired from any possible problem caused by the connector pins at the other end of the cable making accidental contact with frame ground.

Figure 9. Location codes for the DC-UPS (Models 961, 96E) (rear)
Have the customer remove power to the DC-UPS DSU being repaired.
1. Instruct the customer to switch off the circuit breaker that supplies mainline ac voltage to the power receptacle for the DC-UPS DSU you are repairing.
  Attention: Use lockout and tagout procedures as defined in the Electrical Safety for IBM® Customer Engineers.
2. Observe the rear of the DC-UPS DSU.
  Is the LOCAL AC LED (Figure 10) indicator off?
  - Yes, the customer has removed power from the correct DC-UPS DSU. Continue with the next step.
  - No, stop. The customer has not removed power from the correct DC-UPS DSU. Notify the customer. When you can answer yes above, continue with the next step.
At the DC-UPS DSU being repaired, set the CB1 main line switch to Off (down). See Figure 10. This is the DC-UPS DSU which still has the signal cable attached at Ex-J9.
Figure 10. DC-UPS DC supply unit (DSU)
At the DC-UPS DSU being repaired, disconnect the mainline power cable. Push the two release levers . See Figure 10.
If you are replacing the lower DC-UPS DSU (E2), do the following:
1. Loosen the cable ties , for the power cables that cross behind the DC-UPS DSU. See Figure 11.
2. In the following steps, move those cables out of the way as needed.
Figure 11. Power cables behind lower DC-UPS DSU (E2)
At the DC-UPS DSU being repaired, disconnect the DSU-to-DSU power cables from J3-1, J3-2 and J3-3 (, and ). See Figure 10.
Restrain the cables to allow the DSU to be removed and prevent the recessed connector contacts from touching other metal objects such as the DC-UPS chassis.
WARNING: High voltage is present at the recessed contacts of the shielded connectors on the DSU-to-DSU power cables.

Note: If a J3-1, J3-2 or J3-3 cable connector will not release, check the following.
Each connector has two release latches interconnected by a plastic tab. If that tab breaks, you need to release both latches.
At the DC-UPS DSU being repaired, disconnect the remaining cables.
Locate the green and yellow ground cable to the left of the mainline power connector. See Figure 10.
Does the new DC-UPS DSU FRU have a green and yellow ground cable?
- Yes, at the DC-UPS DSU being repaired, disconnect the green and yellow ground cable at the rack end. Continue at the next step.
- No, disconnect the green and yellow ground cable from the DC-UPS DSU being repaired. Continue at the next step.
At the front of the rack, remove the BSM set cover (if present) from the BSM set enclosure.
1. At the bottom of the cover, pull the knob out on both fasteners.
2. Pull the bottom of the cover away from the BSM set.
3. Lift the cover up until the two top sheetmetal tabs release from the BSM set enclosure.
Gently slide each primary battery service module 1 inch (2.54 cm) out of its enclosure so it undocks from the DC-UPS.
1. At the front of the rack, remove the retaining screw (Figure 12) at the top of each primary battery service module in the DC-UPS being repaired: Ex-E12, Ex-E11(if present), Ex-E10 (if present). See Figure 13.
2. Do not disconnect the power cable from primary battery service module connector J20 .
Figure 12. Battery service module set

Figure 13. Base rack locations, front and rear
At the rear of the rack, unscrew the four screws securing the upper section of the DC-UPS DSU to the sheet metal chassis. See Figure 10.
Remove the upper section of the DC-UPS DSU.
- Figure 14 shows a ruler label that indicates when the support by the lower section ends.
- Pull on the upper handle . See Figure 10.
- Support the bottom with your other hand.
- Remove the upper section from the rack.
Figure 14. DC-UPS upper section ruler label
Unscrew the two screws securing the lower section of the DC-UPS to the sheet metal chassis. See Figure 10.
Remove the lower section of the DC-UPS DSU. See Figure 15.
- Hold the left side release lever up.
- Pull on the lower handle and begin to slide the lower section out.
- After the lower section is clear of the release level, support the bottom with your other hand (Figure 15).
- Remove the lower section from the rack.
Figure 15. DC-UPS DSU lower section left side release lever

Compare the new and old DC-UPS DC supply unit (DSU) input phase selection settings

About this task

The DC-UPS DSU input phase selection settings must be correct for the type of power the customer is providing. If the settings are incorrect, the DC-UPS fails to power on.

Procedure

Determine the input phase selection settings for the old DC-UPS DSU.
- Refer to Figure 16 and Figure 17.
- Determine the power type (Three-phase low voltage (200 - 240 V), three-phase high voltage (380 - 415 V), or single-phase (200 - 240 V). Observe the P12, P13 connections.
Figure 16. DC-UPS input phase selection

Figure 17. DC-UPS input phase selection label location
Are the new DC-UPS input phase selections P12, P13 cable connections set the same as the old DC-UPS?
- Yes, go to Install the DC-UPS DC supply unit (DSU).
- No, go to the next step.
On the new DC-UPS DSU do the following:
1. Loosen the thumbscrew and open the DC-UPS input phase selection cover.
2. Reconnect the P12 and P13 cables to match those on the old DC-UPS DSU.
3. Close the DC-UPS phase selection settings cover and tighten the thumbscrew.
4. Go to Install the DC-UPS DC supply unit (DSU).

Install the DC-UPS DC supply unit (DSU)

Procedure

Install the lower section of the DC-UPS DSU.
1. Ensure the CB1 main line switch is Off (down).
2. Slide the lower section in.
3. Raise the retaining latch as needed to ensure the section is fully seated. See Figure 15.
4. Ensure the two screws are securely tightened.
Connect the green and yellow ground cable. Ensure the washers are properly installed. Refer to the other DC-UPS if needed.
1. If you are connecting ground cable to DC-UPS DSU, the installation order is:
  1. Star washer (against DSU chassis)
  2. Ground cable lug
  3. Standard washer
  4. Split washer
  5. Nut
2. If you are connecting ground cable to system frame, the installation order is:
  1. Star washer (against frame)
  2. Ground cable lug
  3. Nut
Install the upper section of the DC-UPS DSU. Ensure that the serial number on the upper section matches the lower section.
Ensure that the four screws are securely tightened.
If the new DC-UPS did not include the fan assembly on the upper section, transfer the fan assembly from the original DC-UPS DSU. The fan assembly is held in place by the three screws . See Figure 10.
Connect the fan assembly cable to the Ex-J4 connector. See Figure 9.
At the front of the rack, insert the primary battery service modules. Install the retaining screw at the top of each battery service module. See Figure 12.
Install the BSM set enclosure cover (if removed).
1. With the bottom of the cover held out some, insert the cover top tabs into the BSM set enclosure slots.
2. Bring the bottom of the cover against the BSM enclosure.
3. Ensure both fasteners are seated and then push the button in to latch them.
4. Give a gentle pull to the bottom of the cover to ensure that it is fastened.
At the rear of the DC-UPS DSU being repaired, connect the DSU-to-DSU power cables at J3-1, J3-2 and J3-3 (, and ). See Figure 10. Take care that the recessed contacts of the connectors do not touch other metal objects such as the DC-UPS chassis.
WARNING: High voltage is present at the recessed contacts of the shielded connectors on the DSU-to-DSU power cables.
At the DC-UPS DSU being repaired, connect all other cables EXCEPT:
- J9 communication
- Mainline power cable
At the DC-UPS DSU being serviced, ensure the CB1 main line switch is Off (down).
Connect the mainline power cable to the DC-UPS and ensure both latches are secure.
Instruct the customer to switch on the mainline circuit breaker that supplies mainline AC voltage to the power receptacle for the DC-UPS you are repairing.
Set the CB1 main line switch to On (up).
Note: The DDM and MAIN LEDs might flash for a short time. You check them again in a later step.
At the DC-UPS DSU being repaired, verify the LOCAL AC LED is lit solid.
If the LOCAL AC LED is not lit, recheck the following:
- The input phase selection jumpers (P12, P13) were set correctly
- The mainline power cable is securely connected
- The correct mainline circuit breaker has been switched on
- The CB1 main line switch has been switched on
If the LOCAL AC LED is still not lit after rechecking the items above, do not continue. Contact your next level of support.
At the DC-UPS DSU being repaired, verify the DSU MAIN output (J2-1, J2-2, J2-3) and DDM output (J1-1, J1-2, J1-3) LEDs are lit solid.
If the DSU MAIN and DDM output LEDs are not lit solid, do not continue. Contact your next level of support.
At the DC-UPS DSU being repaired, connect the Ex-J9 DSU to DSU communication cable at the bottom right. See Figure 9.
At the DC-UPS DSU REMAINING IN CUSTOMER USE, connect the Ex-J9 DSU to DSU communication cable at the bottom right. See Figure 9.
Note: At the DC-UPS DSU being repaired, the DSU Service amber LED should be flashing. If the LED is not flashing, you can still continue the repair.
If you are repairing Rack-2, 3 or 4, observe the rack operator panel LEDs on the upper right of the rack front cover. See Figure 18.
- The upper green LED is for the upper DC-UPS (E1).
- The lower green LED is for the lower DC-UPS (E2).
Is the green LED for the DC-UPS you just repaired lit solid or slow flashing?
- Yes, continue at the next step.
- No, ensure the cable is properly connected to the DC-UPS DSU J8 connector. The cable can be hot-plugged.
  If the LED is now properly lit, continue at the next step.
  If the LED is not lit, the possible failing FRUs are:
  - Rack identity card to DC-UPS cable
  - Rack identity card
  - Rack identity card to operator panel LED assembly cable
  - Rack operator panel LED assembly
  After the LED is working correctly, continue at the next step.
  Note: E1-J8 (Upper DC-UPS DSU) cable goes to C5-J1 (rack identity card).
  E2-J8 (Lower DC-UPS DSU) cable goes to C5-J2 (rack identity card).
  C5-J3 (rack identity card) cable goes to rack operator panel LED assembly.
Figure 18. Rack operator panel LEDs on upper right of rack front cover
If you removed the rear door latch bracket , reinstall it now. See Figure 8.
Reinstall cable brackets and cable ties that were removed. Ensure that the cables are routed correctly.
Remove the upper and lower PDU service tools and return them to the document enclosure (front upper left of Rack-1).
Rotate and fasten the PDUs to the closed position.
If you removed the right rear cover, reinstall it now.
Close the right rear cover and reinstall the two security screws that prevent customer access.
Exit this service information center parts exchange procedure and return to the procedure that sent you here.