Daewoo G1-MECHA Service Manual

Technical Service Guide

G1–MECHA DECK UNIT

1. MECHANICAL DESCRIPTION

1-1. CHARACTERISTIC OF G-MECHA MECHANISM

1) G-Mecha follows the VHS STANDARDS and corresponds to the NTSC/PAL TV.

2) G-Mecha has three motors (Drum Motor, Capstan Motor and L/C Motor).

3) G-Mecha uses L/C Motor to drive Front Loading.

4) G-Mecha realizes its mode by the 4-bit mode signal which is executed by the Mode Switch driven by a L/C Motor.

5) G-Mecha is a slim type DECK with 81.5 mm height.

6) G-Mecha has reduced the consuming time of the mode converting, especially picture appearing time on TV by socalled, "The Full Loading System" which keeps the type always wrapped around the Drum.

1-2. MODE DESCRIPTION

1) EJECT MODE

A.In this mode, the Cassette In/Out operation is performed by the CW/CCW rotation of the L/C Motor to which the Front

Loading driving parts are directly related. CASSETTE IN : If the Cassette is completely inserted into the predetermined postion of the Deck, the state of the

Start Sensor is changed from OFF to ON and at the same time the Cassette In is detected. And instantly the Cassette loading is performed and the Mode proceeds to the Stop Mode.

CASSETTE OUT : In this state, the Cassette Holder is located at the entrance of the Front Pannel, the Start Sensor is

ON and only the Cassette In operation can be executed.

B.Mechanical Arrangement

a. The Band Brake is released from the S-Reel Table. b. The S & T-Main Brake are released from the S & T-Reel Table. c. The S-Sub Brake is released to the S-Reel Table. d. The T-Sub Brake is applied to the T-Reel Table. e. The Idler Gear is applied to the S-Reel Table.

Fig. 1-1. EJECT MODE

2) INITIAL MODE

A. INITIAL MODE is performed between EJECT MODE and LOADING MODE. Also this is used as the reference mode

determining whether or not Cassette Down has finished completely when Cassette In is performed and whether or not the unloading has finished when the state proceeds from STOP MODE to EJECT MODE.

B. Mechanical Arrangement

a. The S & T-Main Brake are released from the S & T-Reel Table. b. The Band Brake is released from the S-Reel Table. c. The S-Sub Brake is applied to the S-Reel Table. d. The T-Sub Brake is applied to the T-Reel Table. e. The Idler Gear is applied to the S-Reel Table.

Fig. 1-2. INITIAL MODE

3) LOADING MODE

A. LOADING MODE is performed between INITIAL MODE and STOP MODE. Also this mode is used as the reference

mode which checks for the loading and unloading of the Pole Base.

B.Mechanical Arrangement

a. The Band Brake is released from the S-Reel Table. b. The S & T-Main Brake are released from the S & T-Reel Table. c. The S-Sub Brake is applied to the S-Reel Table. d. The T-Sub Brake is applied to the T-Reel Table. e. The Idler Gear is located near the T-Reel Table.

Fig. 1-3. LOADING MODE

4) REVIEW MODE

A.The Review Search operation is performed in this mode. This mode is obtained by pushing the REVIEW BUTTON in the

PLAY MODE. The L/C Motor rotates until the Cam Switch detects the REVIEW MODE. When the Cam Switch detects the REVIEW MODE, the L/C Motor is stopped and at the nearly time the Capstan Motor starts to rotate CCW.

B.Mechanical Arrangement

a. The S & T Pole Base are fully loaded to the V-Block of the Drum Base. b. The Band Brake is released from the S-Reel Table. c. The S & T-Main Brake are released from the S & T-Reel Table. d. The S-Sub Brake is applied to the S-Reel Table e. The T-Sub Brake is applied to the T-Reel Table. f. The Idler Gear is applied to the S-Reel Table. g. The Pinch Roller is applied to the Capstan Shaft to transport the tape reversely.

Fig. 1-4. REVIEW MODE

5) STOP MODE

A.This STOP MODE is completely performed by means of the loading operation from the INITIAL MODE.

The cassette tape is wrapped around the Drum to perform the other mode operation quickly (Remind that the Fully Loading System realizes the Quck Response and Quick Start Function).

B.Mechanical Arrangement

a. The Tension Pole is on its predetermined position. b. The Pinch Roller is waiting to contact to the Capstan Shaft. c. The Band Brake is applied to the S-Reel Table. d. The S & T-Main Brake are released from S & T-Reel Table. e. The S-Sub Brake is released from the S-Reel Table. f. The T-Sub Brake is applied to the T-Reel Table. g. The Idler Gear is located near the S-Reel Table.

Fig. 1-5. STOP MODE

6) PLAY/RECORDING MODE

A.In this mode, the cassette tape is transported to the T-Reel Table at the constant speed. B.Mechanical Arrangement

a. The Tension Pole is on its predetermined position. b. The Band Brake is applied to the S-Reel Table to execute the TENSION SERVO. c. The Pinch Roller is applied to the Capstan Shaft to transport the tape at the constant speed. d. The S & T-Main Brake are released from the S & T-Reel Table. e. The S-Sub Brake is released from the S-Reel Table. f. The T-Sub Brake is applied to the T-Reel Table.

Fig. 1-6. PLAY/RECORD MODE

7) SLOW/STILL MODE

A.This is the operation which makes the transporting system temperarity stopped (so called "STILL") and the slowly exe-

cuted (so called "SLOW").

B.Mechanical Arrangement

All the Mechanical system is the same as that of PLAY Mode, except that the capstan Brake is applied to the Capstan Flywheel and S-Sub Brake is applied to the S-Reel Table.

Fig. 1-7. SLOW MODE

8) BRAKE MODE

A.This mode is a mechanical mode which lies in between SLOW MODE and FF/REW MODE. If either STOP/EJECT BUT-

TON or PLAY BUTTON is pushed in the FF/REW MODE, FF/REW operation is stopped quickly.

B.Mechanical Arrangement

a. The Pinch Roller is released from the Capstan Shaft. b. The Band Brake is released from the S-Reel Table. c. The S-Sub Brake is applied to the S-Reel Table. d. The T-Sub Brake is applied to the T-Reel Table. e. The S & T-Main Brake are applied to the S & T-Reel Table.

Fig. 1-8. BRAKE MODE

9) FF/REW MODE

A.In this mode, the cassette tape is rewound to the S & T-Reel Table at the high speed by the CW/CCW rotation of the

Capstan Motor which is directly related to the S & T-Reel Table. If the Start/End Sensor is on during this operation, it returns to the STOP MODE and executes Auto Reverse/Forward Search. During the FF/REW operation, the Drum continues to rotate with the tape wrapped around it and the tape is contacted to the Control Head that reads the Viss Signal.

B.Mechanical Arrangement

a. The Pinch Roller is released from the Capstan Shaft. b. All Brakes are released.

Fig. 1-9. FF/REW MODE

ANGLE

MODE

MECHA MODE

CAM SWITCH

CAM (1)

RELAY LEVER

CAM ANGLE

CAM (2)

LOADING RACK

CAM (3)

PINCH LEVER

CAM ANGLE

CAM (4)

F/L RACK

CONNECT PLATE

S,T-MAIN BRAKE

S-SUB BRAKE T-SUB BRAKE

CAPSTAN BRAKE

BAND BRAKE

REEL DRIVE

6 7 8

10 11

EJECT INITIAL LOADING/UNLOADING REVIEW STOP PLAY SLOW FF/REW

0° 75° 190° 207° 239° 256° 324°

190° 208.1°73.8°0° 240° 258° 326.9°

190.8°0° 207.5° 239.8° 256.8° 324.5°

R23.5

63°

69°

R26

179°

185°

R23.5

195°

203°

R20.9

245°

253°

268°

R18.3

300°

304°

321°

R14.3

R10.75

83°

R26.2

133°

R12.8

148°

R10

167°

R10

183°

R6.7

R13

82.7°

R23.276

185.7°

180.7° R23.3

190.7°

198.7° R22

226.7°

239.7° R24.2

260.4°

263.7°

R23.3

315.7° R15

61.37°

* F/L RACK STROKE : 0~31.46

* CONNECT PLATE STROKE : 0~-3~0~3~3~4.5~4

63°

69°

179°

185°195°

203°

245°

253°

268°

R18.3

300°

321°

30.4°

L H

L S

L: release H: application

S: SLIP D: DIRECT

L: release H: application

1-3. CAM SWITCH TIMING CHART

1-4. WIRING DIAGRAM

DRUM M/T

FE HEAD

CN-D

END SENSOR

CN-A

HEAD DRUM

CN-B

LED

ACE HEAD

CN-C

LC M/T

CAM

CN-E

START SENSOR

REEL SENSOR

CN-A (2 HEAD MONO)

1 VR 1 2 COMMON 3 VL 1 4 GND

§ (4 HEAD MONO) 1 VR 2

2 COMMON 3 VL2 4 GND 5 VR1 6 COMMON 7 VL1

REC SAFETY SW

CN-B

1 M 12V 2 DRUM CTL 3 DRUM PG 4 M GND 5 DRUM FG 6 ON/OFF 5V 7 F(L)/R(H) 8 CAP FG 9 CTL REF

10 CAP DRIVE 11 I LIMIT 12 M 12V

13 M GND 14 GND

CN-C

1 GND 2 CAM D 3 CAM C 4 CAM B 5 CAM A 6 TAPE START 7 TAPE END 8 REEL PULSE 9 REC SAFETY

10 EVER SAFETY 11 FL/LC (–) 12 FL/LC (+)

CN-D

1 GND 2FE

CN-E

1 CTL 2 CTL 3 AUDIO 4 AUDIO 5 A ERASE 6 GND

* : applied to only record model.

§ : applied to only 4 head mono model.

B. BOTTOM VIEW

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