Troubleshooting - Minelab F1A4 Service Manual

5.1.2 Sensitivity Troubleshooting
5.1.2.1 Sensitivity Test Procedure
Hold the Test Piece Mine Detector in one hand, with the end containing the
target away from the Coil. Move the Test Piece Mine Detector towards the centre
of the coil until it lightly touches the centre of the coil and then move it sideways off
the coil (the Test Piece Mine Detector should be moved slowly and smoothly during
this procedure). A soft but distinct change in the threshold tone should be heard.
P0263-B

5.1.2.2 Troubleshooting

If a response is not heard whilst moving the Test Piece Mine Detector
across the Coil, replace the Coil. If a response is still not heard, remove the 6
screws from the front panel, pull the front panel away from the case, and check the
wiring to the PCB from the Front Panel and repair as necessary. If the wiring if
found to be OK, the PCB is defective. Go to 5.2.4 for the PCB replacement
procedure.
5.1.3 Ground Balance Troubleshooting
5.1.3.1 Ground Balance Test Procedure
The F1A4 should initially detect the GB Test Piece (a change of threshold
tone will be heard) as the GB Test Piece is moved to and from the Coil. The F1A4
will then become "balanced" to it, i.e. the F1A4 threshold will remain stable as the
GB Test Piece is moved to and from the Coil.
F1A4 Field Service Manual – Level 1 and Level 2 Maintenance
While holding the Off/Search/Balance switch in the Balance
position, move the GB Test Piece up and down,
approximately 25 to 100mm from the Coil.
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