TM 5-3810-306-34
TABLE 3-1. DIRECT AND GENERAL SUPPORT TROUBLESHOOTING (CONTD)
Malfunction
Test or Inspection
Corrective Action
Step 5. Reconnect plugs (rod and piston) to pressure transducers and check voltages on CPU terminal board at terminal
block X1. (Refer to page 3-82.) Readings should be:
Boom fully retracted:
Between Pin 19 and Pin 21 = 0 Vdc + 20 mV
Between Pin 14 and Pin 16 = 0 Vdc + 20 mV
Boom fully extended:
Between Pin 19 and Pin 21 = Maximum -1 Vdc
Between Pin 14 and Pin 16 = Maximum -1 Vdc
If OK go to Step 6.
a.
Faulty wiring between CPU and pressure transducer. Repair as necessary.
b.
Replace defective transducer. (Refer to page 14-20.)
Step 6. Disconnect hydraulic pipes from pressure transducers (rod and piston) and check voltages on CPU main board.
(Refer to pages 3-83 and 3-84.) Readings should be:
Between test points MP15 and MP4 = 500 mV
Between test points MP15 and MP5 = 500 mV
If OK go to Step 7.
a.
Adjust voltage readings as follows:
Adjust reading between MP15 and MP4 by turning adjustment screw at P4.
Adjust reading between MP15 and MP5 by turning adjustment screw at P5.
b.
If unable to adjust, replace defective transducer. (Refer to page 14-20.)
Step 7. Bad data transfer between CPU and console.
a.
Refer to Malfunction No. 87.
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