Nikon AF-I Nikkor ED 300mm f/2.8D IF, Repair Manual

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JAA33751-R.3646.A
- Ａ4・AF-S VR300/2.8G -
Amplitude
CH1
CH2
Fig. 1
⑥
In case the amplitude is small, when the deformation
is detected in the GMR head, correct the deform
of the GMR head. On the other hand, when such
correction is impossible or no deformation is
detected, replace the GMR unit. (Fig.2)
Note: When adjustments are made, prevent the
magnetic tape and MR head from touching the
magnetized driver bit. Otherwise, the magnetic
data may be damaged.
GMR head
Magnetic surface
#218×2
Adhesive: Screwlock
Fig. 2
● Oscilloscope setting
V/Div (ch1) : 50 mV
V/Div (ch2) : 50 mV
Coupling : AC
Time/Div : 5 m Sec
Trigger Mode : NORMAL
Trigger Coupling : AC
(1) How to inspect:
①
Turn the switch 1 to OFF, switch 2 to OFF and switch 3 to ON of the Switch tool.
②
Confirm that the electric current and voltage of the connected rated voltage power-supply are set values,
then turn it ON.
③
Set the oscilloscope and turn the focus ring manually.
④
Check the waveform of the oscilloscope by stopping with "START/STOP" key.
Note
：
The waveform varies according to the rotational speed of the focus ring. So change "Time/Div” setting
accordingly.
Standard
:
Amplitude of all pulses/
waveforms is 80mV or more.
Note : Check the waveform by moving the
focus ring back and forth from the
infinity-end to the close-end positions
entirely.
⑤
In case large waveform-noise is detected, use the FILTER function.
How to set FILTER function (e.g. DL1540 manufactured by YOKOGAWA
）
1. Press the FILTER button.
2. Select “Smooth” of the menu on screen and turn it ON.