Nikon AF-S DX Zoom Nikkor 18-135/3.5-5.6G ED, Repair Manual

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JAA79651-R.3695.A
- Ａ34 ･ AF-S DX 18-135/3.5-5.6G -
Inspection of Lens operations
Check the lens operations by using a personal computer after assembling.
○ Check by personal computer
● Check by the following considerations:
1. MR encoder operations
・
Drive the scanning of lens and check the total number of pulses.
・
In case the MR head of the MR encoder and the magnetic tape are misaligned, the number of pulses
becomes out of standard.
2. Lens-servo stop accuracy
・
Check the number of overrun/underrun pulses (deviation of the stop position from the target position) per
the specified lens driving.
・
In case the irregularity of mechanical operations does not take place in the focus ring driving unit, the
underrun tends to occur if the rotation of the segment-gear ring unit is heavy, while the overrun tends to
occur if it is light.
3. Lens-servo time
・
Check the servo time (from starting and stopping the servo) when driving the specified lens by using the
oscilloscope.
・
In case the irregularity of mechanical operations does not take place in the focus ring driving unit, the
servo-time tends to be long if the rotation of the segment-gear ring unit is heavy, while the servo-time
tends to be short if it is light.
4. Switches and lenses
・
Check the ON/OFF operations of switches and the operating condition of the zoom and distance encoder.
● After inspections
1. When the MR encoder operations are NOT up to the standard:
Readjust the MR duty. (ref. Page A32.)
In case the pulse is not up to the standard, recheck "GMR output check" (ref. Page A19).
In case the pulse meets the standard, replace the SWM base unit, mechanical parts which drive the
focus sliding tube, etc.
2. When the lens-servo stop accuracy is NOT up to the standard:
Check the output waveform of the MR encoder. If it is normal, replace the SWM base unit,
mechanical parts which drive the focus sliding tube, etc.
3. When the lens-servo time is NOT up to the standard:
Readjust the driving frequency and motor control.
In case the lens-servo time is not up to the standard even after the readjustment, replace the SWM
base unit, mechanical parts which drive the focus sliding tube, etc.