Mechanism Section; Tape Section - Sharp JC-K99 Service Manual

JC-K99 ©
Preparation (See Figs. 18—1 and 18—2.)
1. Connect the 4 motor lead wires (A, B, C, D) and the 2 sole-
noid lead wires (E, F). (Match the polarity.)
2. Connect a dummy switch and turn it OFF.
3. Connect the tape travel dummy signal lead wire (G).
4. Supply power. (+1.5 V)
Operation
1. PLAY
(1) Press the PLAY/DIR button.
(2) When the motor runs and the solenoid is cancelled, turn
the dummy switch ON.
2. DIRECTION
(1) When the PLAY operation finishes, press the PLAY/DIR
button again.
(2) When the solenoid is cancelled, turn the dummy switch
OFF.
(3) When the solenoid adsorbs and is cancelled again, turn
the dummy switch ON.
(4) Set the FWD/REV selector switch to the opposite po-
sition.
ADJUSTMENT x2
As for adjusting method refer to the relevant explanation
in Service Manual ''ADJUSTMENT PROCEDURES OF AU-
DIO PRODUCTS".
MECHANISM SECTION
Driving Force Check
Torque Meter | Specified value
Head Azimuth
* This mechanism does not require adjustment.
Tape Speed
Test Tape Adjusting | Specified Instrument
____ {| Point | vatue 7 _ Connection
MTT-111 VR11 3,030 + 15 Hz Headphones
socket
(Load resistance:
ell
woalil
k e
16 ohms)
3. Using FF/REW/STOP in the PLAY Mode
(1) Press the STOP or FF/REW button.
(2) When the solenoid is cancelled, turn the dummy switch
OFF.
4. Using FF/REW in the STOP mode
Turn the dummy switch OFF, and press the FF/REW
button.
5. Tape end
(1) Set the unit to one of the above operation modes.
(2) Disconnect the tape travel dummy lead wire (G).
Notes:
1. When the remote control switch operation does not func-
tion, turn the dummy switch OFF, and earth pin 26 of IC5
or short-circuit both electrodes of C89 for 1 second.
2. Be careful not to bend the flexible PWB. Handle the main
PWB carefully.
3. When reassembling, solder the lead wire again taking care
not to apply solder thickly.
TAPE SECTION
Position of each switch or control
Volume | Max
| Dolby NR switch
| OFF
|
fee selector switch | Normal =k
Extra bass switch
| OFF
al
|
| Reverse mode switch (enn)
Playback Amplifier Sensitivity
Test Tape MTT-150
Instrument
Connection
TP1: Pin 14 (L) of IC2
TP2: Pin 3 {R) of IC2
| Specified valve Adjusting Method |
When lower than the
specified value: *1
When higher than the
specified value: *2
24.5 mV + 1 dB
*1: Add R27 and R28 (3.9 Kohms).
[The resistance to R11 and R12 (470 ohms) is 419 ohms. ]
*2: Cut the pattern and add R25 and R26 (47 ohms).
{The resistance to R11 and R12 (470 ohms) is 517 ohms.]}
: Clock frequency adjustment
Instrument
Connection
| TP3 and earth.
Specified Value Adjusting Method
More than 2.5 kHz: *3
{ | Less than 2.0 kHz: 40
When 1.2 V DC,
2.0 - 2.5 kHz
*3: Add 27 PF.
*4: Connect 3.3 Mohms to R97 in parallel.
27 PF VCCCTV1HH270J _
3.3 Mohms
VRS-CY 1JB335J
~17—