T/R Quad Extremity Coil Replacements

Prerequisites

Table 1. Personnel requirements
Required persons	Preliminary requirements	Procedure	Finalization
1	Not Applicable	30 minutes	Not Applicable

Table 2. Tools and test equipment
Item	Quantity	Effectivity	Part number	Manufacturer
Flat-head Screwdriver for No. 6 size screws	1	Cable Replacement	-	-
Flat-head Screwdriver for No. 4, 6 and 10 size screws	1	Mechanical Components	-	-
Digital Multimeter	1	Testing Cable Functionality	-	-
Loctite® 222 (12-month shelf life)	One 10 cc bottle	-	46-170683P1	-

Follow this procedure to replace field replaceable units on the T/R Knee/Foot Coil by Invivo.

Notice

A Cable Continuity Check must be performed by an Authorized Service Engineer only.
Select the Ohmmeter function on the Digital Multi-Meter (DMM).

Figure 1. HD System Connector (View from Cable End)
Refer to the previous illustration. Using the DMM, verify continuity of the cable by performing a continuity check on the system connector:
- From A1 to A2 pins
- From M9 to M10 pins
Remove the six brass screws from the underside of the cable connector housing, and unplug the cable from the Printed Circuit Board (PCB).
Access the reference points on the exposed interconnect PCB, and perform continuity checks on the following reference points from the PCB to the system connector block (Figure 1).

From To
MC-1 C1
REF LOAD H3
TX F2
PA +10 VDC M3
MC BIAS J1
COIL ID M7
COIL ID RTN M8
While checking, flex the cable to test for intermittent open and short conditions within the cable.
- If the cable fails any of the tests, contact GE Customer Service to order a new cable assembly.
- If the cable passes the tests, plug the interconnect PCB back into the Preamp PCB, and secure the cable to the underside with six brass screws removed previously.

Notice

Cable Replacement must be performed by an Authorized Service Engineer only.
Remove the bottom screws from the extended housing.

Figure 2. Cable Replacement
Carefully remove the top cover and set it aside.
Unseat the cable from the cradle, carefully remove the small PCB with the 20-pin connector from the large PCB, and set the cable assembly aside.
Replace the cable assembly with the new one, mating the 20-pin connector in the socket.
Seat the cable assembly into the cradle and replace the cover, ensuring the cable end sits level and upright.
Replace and hand tighten the bottom screws in the cover.
Scan the coil to ensure proper assembly.

Lift the coil locks on both sides of the coil, and slide the coil from side to side. (The coil must slide freely back and forth on the base without binding or grinding.)
Lock the coil in the center of the base, and check the bottom of the base to ensure the four rubber feet are tight.

Note:
Make sure the coil latch is secure and the base lock is fastened.

Remove the two 6-32 x 0.438 FHMS brass screws from the housing, and replace the draw latch with the new one.
Use Loctite 222 on the brass screws, insert them into draw latch and hand tighten.
Test the draw latch to ensure proper assembly.

Mate the new handle and cover pieces together, and fasten with the 4-40 x 0.375 PHMS brass screws.
With both handle locks in the upright position, pry one side of the handle lock from the cradle on the side of the housing, and slide the lock assembly from the T-Bracket.
Use Loctite 222 on the brass screws, replace the lock assembly with the new one, and secure with the screws.
Place one end of the lock assembly into the cradle of the housing, and maneuver the other side into the cradle.
Test the lock mechanism to ensure proper assembly.

Remove the coil lock as described in Step 2 and replace the T-Bracket with the new one.
Replace the lock assembly per Step 3 and Step 4.
Test the lock mechanism to ensure proper assembly.