1.5T 12-Channel Body Array Coil Troubleshooting

Example:

1. In this example, Test 1, Image 2 fails SNR.

2. This image 2 corresponds to the anterior element 6A.

3. Test 2 passes all images, however, does not test element 6A.

4. Test 3, Image 2 passes, but now it is testing anterior element 2A.

Conclusion: Receive chain from coil to recon is good; however, element 6A on the anterior part of the coil is bad. Replace the anterior FRU.

To view signal images, use Image Display in a 3 X 3 matrix. This will show each of the intermediate images (1 through 8), plus the composite image as image 9.

• Images from coil elements being tested should have significant higher W/L values than images from elements not being tested.

• Images from coil elements being tested, but that have significantly lower W/L values, would be considered failing.

Before removing the cable assembly from the coil, visually inspect all coaxial connectors and pins on the coil connector. The figure below shows the pin layout of the single coil connector for an HDx or HDxt system. If there are any broken, deformed or recessed pins or coaxial connectors, replace the cable assembly.

Notice
	Under no circumstances should the continuity of the center pin of the coax connectors be measured. They are extremely fragile when improper tools are used.

1. Remove the cable assembly from the coil. Refer to Cable Replacement.

2. Use a digital volt meter (DVM) to check the resistance between the pin in the different columns and the corresponding DC wire. The table below shows these pins and corresponding DC wires. The resistance should be 0.2 ±0.2 Ohm. Use Figure 6 as a reference. If any resistance reading is not within this range, perform a Cable Replacement.

3. Table 1. Pins and Connected DC Wires

   Color	Pin
   Red	M3
   Shield	M5
   Black/Grnd	M6
   White	M7
   Blk/Clr	M8
   Shorted together	A1 to A2
   	J9 to J10
   	M9 to M10

4. Check if any pin in the table above is shorted to ground. The outside conductor of a coaxial connector in column C, D, G, or H can be used as ground. If any pin is shorted to ground, perform Cable Replacement.

1. Remove the cable assembly from the posterior and unplug the P-connector from the anterior. Refer to Cable Replacement.

2. Use a DVM to ensure an open circuit condition exists between the system connector and posterior coil-side RF cables. (See Figure 7 and Table 2.) Similarly, ensure an open-circuit condition between the system connector and the anterior P-Connector. (See Figure 8 and Table 3.) Use Figure 9 as a pin layout reference for the P-connector.

3. If the test fails, perform Cable Replacement.

4. Check for continuity in DC cables from the system connector to anterior connector and system connector to posterior.

5. 

   Table 2. Hypertronics/P-Connector Single Connector RF Allocation for Posterior

   P-Connector	Hypertronics Connector	SMB Connectors from Cable Trap-Coaxial Cable Color
   R9	G1	Clear coax
   R10	G2	Brown coax
   R11	G3	Red coax
   R12	G4	Orange coax
   R13	H1	Yellow coax
   R14	H2	Black coax

   Table 3. Hypertronics/P-Connector Single Connector RF Allocation for Anterior

   P-Connector	Hypertronics Connector	P-Connector (RF from Left to Right)
   R1	C1	O6
   R2	C2	O1
   R3	C3	O4
   R4	C4	O3
   R5	D1	O5
   R6	D2	O2

   

   

6. Measure the open circuit condition P-connector and P-connector DC pins or between Hypertronics connector and P-connector DC pins. (See Table 4.) Use Figure 9 as a pin layout reference for the P-connector.

7. If the test fails, perform Cable Replacement.

8. Table 4. Hypertronics/P-Connector Single Connector DC Allocation for Anterior

   P-Connector	Hypertronics Connector	P-Connector DC Pins
   R1	C1	Pin 10
   R2	C2	Pin 5
   R3	C3	Pin 9
   R4	C4	Pin 6
   R5	D1	Pin 8
   R6	D2	Pin 7

9. Measure the open circuit condition between P-connector and 8-pin header or between Hypertronics connector and 8-pin header. (See the table below.)

10. If the test fails, replace the cable.

1. Measure resistance using a DVM between the system connector pins and P-connector DC pins. See the table below, columns 3 and 4.

2. Measure resistance between the system connector DC pins and posterior 8-pin header. See the table below, columns 1 and 2. The resistance between the pins should be ≤2.7Ω.

3. If the resistance measured does not pass specification, perform Cable Replacement.