Akai CD-57 - Front Side

IV. ELECTRICAL ADJUSTMENT
{ABOUT THE TEST MODE]
*This TEST mode is used for the adjustment or check.
* How to set into the TEST mode.
Turn the power on, while pressing the [>/II, aa and >>|
buttons on the front panel.
*How to change the TEST mode number.
Press the 4 button, then advance a TEST mode num-
ber, when TEST mode number is return to initial TEST
mode number, press mm button.
STEP | ADJUSTMENT
1. TEST DISC
2. MODE or TEST mode
3. TEST POINT and ADJUSTMENT
parts.
4.(*) REMARK, (*) RESULT
¢
4,
o
Test point
ADJ.part
*TEST mode condition and DISPLAY
TEST MODE DISPLAY
2.PLAY
of connector P2.
*0.8 to 1.2 Vp-p.
TRACK MIN SEC |
1 arom
Lb lute I ft
¢ Indicated that unit is set into
the TEST mode.
[3 | TRACKING SERVO GAIN
1.Test disc 5A (AT-751330)
3.Pin © (TRK) of connector P2 / VR 3
4.+ Connect an oscilloscope to pin © (TRK)
TRACK MIN SEC |2
raoord Ft rt
Lio ity Lit
¢ Indicated that the end of FO-
CUS SEARCH.
TRACK MIN
Bee SEC (23
rior
mary
Lio wt. Ltt
* Set into the CLV-S mode.
Tracking servo gain is set to
_, SEC 1234
rir
Cio ita Lo fot
| Track MIN
mt
|__same as “JUMP” mode.
| * Tracking servo is on.
* Unit in to the nomal play mode
except anti shock is “OFF”.
« After this, track NO. and time
counter become normal indica-
tion
¢ Anti shock is “ON” and unit into
nomal condition.
¢ If press the a button again,
unit will enter the nomal “power
ON” mode.
1.Test disc 5A (AT-751330)
2.Test mode 3
3.TP 3 (TE) / VR 2
4.«Connect an oscilloscope to TP 3 (TE)
aA eonN
fa)ves (TRK GAIN)
TP4
2.10 seconds after power is on.
3.TP 5 (WFCK) / VR 5
4.* Connect a frequency counter to TP5
(WFCK).
*Connect TP 1(EFM) to TP 2 (GND) by
jumper wire.
*7,350 + 50 Hz
ea VR4
(FCS GAIN)
(FCS OFFSET)
|5 | FOCUS OFF-SET
1.Test disc 5A (AT-751330)
2.Test mode 2 and 1
3.TP 4 (FE) / VR 1
4.*Connect a digital DC voltmeter to TP 4
(FE) and check voltage A in the test
mode 2, then press STOP button and
adjust voltage B so that the reading on
the digital DC voltmeter is same as
voltage A.
*A=B
FOCUS SERVO GAIN
1.Test disc 5A (AT-751330)
2.PLAY
3.Pin ® (FCS) of connector P2 / VR 4
4.eConnect an oscilloscope to pin © (FCS)
of connector P2.
*1.0 to 1.4 Vp-p...
MAIN PCB
Vy
FRONT SIDE
SERVICE MANUAL