SIGNA MR355 / SIGNA MR360
Service Manual
5856356-3EN Revision 5.0
Basic Service Documentation. Copyright General Electric Company.
Object ID: 00000018WIA30601030GYZ
Topic ID: id_13106686 Version: 1.3
Date: Jul 5, 2019 11:18:59 PM

LCC Dock Replacement

Prerequisites

Table 1. Personnel requirements
Required persons	Preliminary requirements	Procedure	Finalization
2	Not Applicable	1 hours	Not Applicable

Table 2. Tools and test equipment
Item	Quantity	Effectivity	Part number	Manufacturer
non-ferrous adjustable wrench	1	-	-	-
non-ferrous flathead screwdriver	1	-	-	-
socket wrench	1	-	-	-
allen screwdriver	1	-	-	-

Table 3. Safety

DANGER

FATAL ELECTRIC SHOCK HAZARD!!

TO PREVENT FATAL ELECTRIC SHOCK, DISCONNECT POWER FROM THE PDU BEFORE YOU PERFORM THE FOLLOWING PROCEDURES.

PERFORM LOCKOUT / TAGOUT PROCEDURE PER GE OSHA LOCKOUT / TAGOUT REQUIREMENTS LISTED IN THE FIELD SERVICE EHS MANUAL & TRAINING 2000 P/N 2135387-200.

Warning

POSSIBLE PERSONAL INJURY!

THIS PROCEDURE REQUIRES REMOVAL OF FERROUS MATERIAL IN CLOSE PROXIMITY TO THE MAGNET.

Therefore, two Field engineers are required at all times.

About this task

Procedure for replacement of the following dock components for 1.5T and 3.0T LCC Magnets.

The dock limit switch board.
The dock gear-motor and clutch assembly.


Last Revised:	April 30, 2007

Removal of Dock

Procedure

DANGER

FATAL ELECTRIC SHOCK HAZARD!!

TO PREVENT FATAL ELECTRIC SHOCK, DISCONNECT POWER FROM THE PDU BEFORE YOU PERFORM THE FOLLOWING PROCEDURES.

PERFORM LOCKOUT / TAGOUT PROCEDURE .

Perform ACGD Lock Out Tag Out.

Undock the patient table and remove it from the scan room.
Disconnect the two cables that are attached to the Dock. These should be the runs going to the Dock Assembly (MG2 A29) and the Dock Limit Switch (MG2 A31).
Using a marker, mark the nut and clamp bracket before removal. The marks will be realigned when the dock is installed later to ensure proper tightening. See Figure 1.

Figure 1. Marking the Nut and Clamp Bracket
Loosen the bolts attaching the dock assembly at the front and at the right and left brackets. See Figure 2. (Figure 5 also shows bolt locations).

Figure 2. LOOSEN DOCK ATTACHMENT BOLTS

Warning

POSSIBLE PERSONAL INJURY!

The Dock Contains Ferrous Materials.

FROM THIS POINT OF THE PROCEDURE FORWARD, DOWNWARD PRESSURE MUST BE CONTINUOUSLY APPLIED TO THE DOCK SO AS TO PREVENT IT FROM BEING PULLED INTO THE MAGNET BORE.

Applying pressure to the top of the dock, completely remove all dock attachment bolts. See Figure 3.

Figure 3. APPLY PRESSURE TO DOCK AND REMOVE ATTACHMENT BOLTS

Use two FEs to pull the dock away from the magnet until the stud in the front is hitting the inner frame. See Figure 4.

Figure 4. PULL THE DOCK AWAY FROM THE MAGNET AS MUCH AS POSSIBLE

Warning

POSSIBLE PERSONAL INJURY!

TO OPPOSE ANY PULL FROM THE MAGNET, FIELD ENGINEERS MUST APPLY CONTINUOUS DOWNWARD PRESSURE TO THE TOP OF THE DOCK EVEN WHEN LIFTING THE DOCK IN THIS STEP.

DO NOT PLACE ANY PART OF THE HUMAN BODY IN THE PATH BETWEEN THE DOCK AND THE MAGNET.

Use two FEs to lift the dock up JUST ENOUGH to clear the top of the stud in the floor. See Figure 5.

Figure 5. LIFT THE DOCK JUST ENOUGH TO CLEAR THE STUD IN THE FLOOR

The two FEs should gently place the dock to the left side of the stud in the floor while still maintaining vertical downward pressure to the dock. See Figure 6.

Figure 6. PLACE DOCK DOWN TO THE LEFT OF THE STUD IN THE FLOOR

Note:
It should not be extremely difficult for two FEs to pull the dock away from the magnet once all bolts are removed. If you do encounter difficulty, check that the brackets are not caught against the front of the magnet. See Figure 7.

Figure 7. WATCH FOR INTERFERENCE BETWEEN THE BRACKET AND THE MAGNET
With two field engineers, one holding each side of the dock, slide the dock away from the magnet front to where the foot of the patient table would normally be located.
When a safe distance away from the magnetic field (at least as far as the foot end of the patient table), two field engineers may slowly lift the dock from the floor and exit the room.

Replacement of Dock Limit Switch

Procedure

The Dock Limit Switch should only be removed AFTER following the procedure above (Removal of Dock) for Removal of Dock.
To remove the Dock Control Assembly, see Figure 8.

Figure 8. REMOVAL OF THE DOCK CONTROL ASSEMBLY
Once the Dock Control Assembly has been detached from the dock mounting support, perform the remainder of this replacement procedure outside of the magnet room.
To access the circuit board internal to the Dock Control Assembly, see Figure 9.

Figure 9. REMOVAL AND REPLACEMENT OF DOCK LIMIT SWITCH BOARD
Replace the Dock Limit Switch Board as shown in Figure 9.
Re-assemble the Dock Control Assembly as shown in Figure 8.
Note:
Realign the marks on the nut and clamp bracket when installing the dock. This is to ensure proper tightening.

Excessive tightening may result in the stud being pulled from the floor.

Re-attach the assembly to the Dock Mounting Support.

Replacement of Gear Motor and Clutch Assembly

Procedure

Warning

POSSIBLE PERSONAL INJURY!

THE MOTOR CONTAINS FERROUS MATERIALS!!

THE MOTOR REPLACEMENT MUST BE PERFORMED OUTSIDE OF THE MAGNET ROOM.

The Motor and Clutch Assembly should only be removed AFTER completing the procedure for Removal of Dock, refer to Removal of Dock.

Remove the upper cover of the dock by un-bolting the four hexbolts. See Figure 10.

Figure 10. REMOVE FOUR HEXBOLTS FROM UNDER DOCK COVER
Slightly lift the cover and disconnect all electrical connections between the cover and the base of the dock assembly. The connections will be the ground connection for the motor and the harness for the dock motor.
Remove the dock cover from the base.
Disconnect the motor's ground lug from the cover. See Figure 11.

Figure 11. MOTOR GROUND LUG REMOVAL
Remove the four mounting screws for the motor. See Figure 12.

Figure 12. REMOVE MOTOR MOUNTING SCREWS
Remove existing motor.
Install replacement motor.
Attach motor by replacing the four mounting screws for the motor. SeeFigure 12 for location of the screws.
Attach the motor's ground lug to the cover. See Figure 11.
Replace the dock cover on the base.
Reconnect all electrical connections between the cover and the base of the dock assembly. The connections are the ground connection for the motor and the harness for the dock motor.
Replace the upper cover of the dock and secure by replacing the four hexbolts. See Figure 10.

Installation of Dock

Procedure

Warning

POSSIBLE PERSONAL INJURY!

THIS PROCEDURE REQUIRES REMOVAL OF FERROUS MATERIAL IN CLOSE PROXIMITY TO THE MAGNET.

Therefore, two Field engineers are required at all times.

With two field engineers, one holding each side of the dock, enter the magnet room and place the dock on the floor where the foot of the patient table would normally be located.

With two field engineers, one applying vertical downward pressure to each side of the dock, slide the dock toward the magnet front.
While maintaining pressure to the top of the dock, position the dock against the base of the magnet to the left of the floor stud at the front of the dock. See Figure 13.

Figure 13. Placement of Dock
Lift the dock just enough to clear the top of the stud in the floor. See Figure 14.

Figure 14. Lifting Dock to Clear Floor Stud
While rotating the dock to the right, align the hole at the base of the dock with the stud and place the dock down into position.
Note:
Realign the marks on the nut and clamp bracket when installing the dock. This is to ensure proper tightening.

Excessive tightening may result in the stud being pulled from the floor.

Use the attachment bolts to secure the dock at the front stud and side brackets. See Figure 15.

Figure 15. SECURE THE DOCK TO THE MAGNET
Connect the cable to the Dock Assembly (MG2 A29) and to the Dock Limit Switch (MG2 A31).
Remove the power lock- out tag-out from the ACGD cabinet and restore power.
Align and dock the table.

What to do next

Finalization

No finalization steps.