DV-NC65H (serv.man13). Adjustment, replacement and assembly of mechanical units - Sharp DVD Service Manual (repair manual). Page 16

Notes:
1. Previously set the tracking control in the center position,

and adjust the ATR signal waveform to maximum with X
value adjustment nut. Thereby the tape run rough ad-
justment is facilitated.

2. Especially the outlet side ATR signal waveform must

have higher flatness.

2. Adjustment of A/C head height and azimuth

1 Perform the initial setting of A/C head position by the

method stated in "8-17 Replacement 3".

2 Connect the oscilloscope to the audio output terminal.
3 Using the alignment tape in which 1 kHz linear audio

signal has been recorded, adjust the height screw so
as to get max audio output.

4 Using the alignment tape in which 7 kHz linear audio

signal has been recorded, adjust the azimuth screw
so as to get max audio output.

5 The adjustment of 3 and 4 twice or three times

repeat, and finally adjust 4.

For X value adjustment
Adjust the X value, turning the gear-
type screwdriver.

3. Tape run adjustment

1 Connect the oscilloscope to PB CHROMA ATR

signal output test point, set oscilloscope sync to
EXT, trigger-input the PB CHROMA signal (head
switching pulse).

2 Rough adjustment of X value

Tentatively fix A/C head arm screws 1  by the method
described in "8-17 Replacement 3".
Playback the alignment tape (VROCPSV) and
shortcircuit between TP803 and TP802 on VCR
Operation PWB. As a result the auto-tracking is
automatically cancelled, so that the X value adjust-
ment mode is set.
Move the A/C head with the X value adjustment gear
driver (JiGDRiVER-6) by the method shown in Fig-
ure 8-34, and adjust the A/C head so as to get the
maximum ATR signal waveform. (Note: When the A/
C head is adjusted, adjust so that the maximum ATR
signal waveform is obtained nearest the position of
initial setting made in 8-17.)

3 Next, press the tracking button (+), (–) and change

the ATR signal waveform from max to min and from
min to max. At this time adjust the height of supply
and take-up side guide roller with the adjustment
driver (JiGDRiVERH-4) so that the ATR signal wave-
form changes nearly parallel.

4 If the tape is lifted or sunk from the helical lead

surface, the PB CHROMA ATR signal waveform
appears as shown in Figure 8-31.

5 Press the tracking button (+), (–) and make sure that

the ATR signal waveform changes nearly parallel.

6 Finally, check tape crease near the reverse guide. If

tape crease is found, adjust tilt screw 45˚ counter
clockwise. Small tape crcase will appear at retain
guide after this adjustment finished.

PB CHROMA
ATR Signal