Daewoo DV-T8T2NZ-QB/M User manual

Service Manual
S/M No. :VT8T2NTEF0
Sep.2000
DAEWOO ELECTRONICS CO., LTD.
http ://svc.dwe.co.kr
Video Cassette Recorder
Model:
DV-T8T2NZ-QB/M
DV-T5T2NZ-QB/M
ALLT-MECHA (Hi-Fi/MONO)
123
456
789
0
LR
DV-T5T2
DV-T8T2
VR-F2PB
✔ Caution
: In this Manual, some parts can be changed for improving, their
performance without notice in the parts list. So, if you need the
latest parts information,please refer to PPL(Parts Price List) in
Service Information Center (http://svc.dwe.co.kr).

1
TABLE OF CONTENTS
SPECIFICATION .......................................................................................................... 2
VOLTAGE CHART ........................................................................................................ 3
CIRCUIT DIAGRAM...................................................................................................... 6
POWER SUPPLY SCHEMATIC DIAGRAM ............................................................................................... 6
SERVO/SYSCON/CBC CIRCUIT DIAGRAM(T-DECK)............................................................................... 7
VIDEO/AUDIO SCHEMATIC DIAGRAM (2/4 HEAD)................................................................................ 8
VIDEO/AUDIO SCHEMATIC DIAGRAM (Hi-Fi) ........................................................................................ 9
PIF SCHEMATIC DIAGRAM (2/4 HEAD) ................................................................................................ 10
PIF&MPX SCHEMATIC DIAGRAM (Hi-Fi) ............................................................................................. 11
WAVEFORMS ............................................................................................................. 12
INSTRUMENT DISASSEMBLY .......................................................................................... 16
ELECTRICAL PARTS LIST ............................................................................................... 21
APPENDIX
TROUBLESHOOTING GUIDES ....................................................................................... 1
POWER CIRCUIT ................................................................................................................................ 1
SERVO / SYSCON / LOGIC CIRCUIT .................................................................................................... 3
VIDEO CIRCUIT .................................................................................................................................10
AUDIO CIRCUIT (Hi-Fi MODEL) .......................................................................................................... 14
AUDIO CIRCUIT (2 / 4 HEAD MODEL) ................................................................................................. 19

2
SPECIFICATION
Note: Specifications are subject to change without notice.
Power Input 100-240 Volts AC 60Hz(Free voltage)
DV-T5T2NZ-QB/M DV-T8T2NZ-QB/M
Power Consumption 17 Watts (4-head Hi-Fi)
17 Watts (4-head)
Operating Temperature 5 degree C to 40 degree C (41 degree F to 104 degree F)
Storage Temperature -30 degree C to 65 degree C (-22 degree F to 149 degree F)
Weight 6.6 Ibs : Net (8.8 Ibs : Gross)
Dimensions 14.2 X 3.6 X9.4 Inches
Recording System
4-head Hi Fi: Four video record/playback heads Rotary helical scan
Luma: FM recording
Chroma: converted subcarrier phase shifted recording
Two audio record/playback heads
Rotary helical scan, 2 channels FM recording
4-head: Four video record/playback heads Rotary helical scan
Luma: FM recording
Chroma: converted subcarrier phase shifted recording
VideoSignal EIA standard; NTSC color
Antenna 75 ohm input impedance
Video Signal Level 1Vp-p (140 IRE standard)
Audio Input Impedance More than 47K ohm
Audio Output Impedance Less than 1.5K ohm
Tape Speed SP: 33.35mm/sec.
SLP: 11.13mm/sec
Maximum Recording Time T-60: 3 hours/ EP (SLP) mode
T120: 6 hours/ EP (SLP) mode
Fast Forward/Rewind Time 3 minutes (T-120 tape)
Tuning System Auto Program/Cable Compatible/Frequency Synthesis (FS)

3
VOLTAGE CHART
A/V CHIP IC (IC301, LA71071M)
PIN NO. REC PB PIN NO. REC PB PIN NO. REC PB PIN NO. REC PB
12.3 2.38 26 2.3 2.57 51 0.82 0.8 76 2.37 2.37
22.3 2.38 27 0 0 52 2.0 2.0 77 1.0 0
32.47 2.4 28 1.6 1.86 53 4.3 4.9 78 2.37 2.4
42.47 2.4 29 1.0 1.0 54 4.9 5.0 79 2.39 2.37
52.47 2.4 30 0 0 55 5.0 2.58 80 2.37 0
62.47 2.41 31 0 0 56 5.0 5.2 81 00.8
72.5 2.41 32 0 0 57 4.9 4.97 82 0.7 0.8
8 0 0 33 0.3 0.3 58 3.58 3.3 83 0.78 0.8
9 0 0 34 0.3 0.3 59 4.9 4.9 84 0.78 0.8
10 5.0 5.0 35 2.0 1.75 60 3.39 3.8 85 0.79 0.8
11 4.9 036 0.9 0.97 61 3.8 3.88 86 0 0
12 0 0 37 1.45 1.56 62 2.5 2.59 87 5.2 5.2
13 0.37 0.3 38 2.58 2.55 63 2.1 2.0 88 4.4 1.8
14 0.36 0.35 39 3.3 3.33 64 2.2 2.2 89 4.39 1.85
15 0 0 40 2.58 2.56 65 3.98 3.96 90 4.39 1.85
16 4.9 0.1 41 4.8 4.8 66 2.0 1.56 91 4.4 1.85
17 4.94 042 2.58 2.58 67 0 0 92 1.53 0.4
18 0 0 43 2.79 2.54 68 2.37 2.38 93 0.67 2.33
19 0 0 44 2.88 2.99 69 2.0 2.0 94 0.83 0
MOTOR DRIVE IC
(IC604, BA6209/KA3082/DBL2084N)
PIN NO. REC PB
1 0 0
20.55 0
30.9 0.88
46.0 6.0
50.01 0.01
60.01 0.01
713.47 13.4
813.48 13.4
90.91 0.91
10 0.5 0.51

4
H-FI IC (IC201, LA72637M)
20 1.53 1.5 45 3.0 3.0 70 1.66 1.49 95 0 0
21 5.1 5.0 46 2.58 2.53 71 0 0 96 2.4 2.4
22 1.0 1.0 47 2.38 2.38 72 2.1 2.17 97 0 0
23 1.33 1.3 48 0 0 73 4.0 4.0 98 0 0
24 2.36 1.4 49 1.78 1.79 74 2.0 1.9 99 3.2 0.12
25 3.0 3.0 50 0 0 75 5.1 5.1 100 3.88 2.37
PIN NO. REC PB PIN NO. REC PB PIN NO. REC PB PIN NO. REC PB
12.4 2.43 17 0.7 0.7 33 2.5 2.5 49 3.49 3.5
2 0 0 18 2.49 2.54 34 0.7 0.7 50 3.0 3.1
32.4 2.43 19 2.49 2.53 35 02.5 51 4.99 5.0
4 0 0 20 2.55 0.4 36 0 0 52 3.3 3.38
52.2 2.24 21 2.53 037 1.64 1.6 53 5.83 5.95
62.49 2.5 22 2.54 0.68 38 0 0 54 2.3 2.34
72.0 2.0 23 05.0 39 0 0 0 55 0 0
80.3 024 05.0 40 4.9 5.0 56 0 0
9 0 0 25 4.9 5.0 41 0 0 57 5.9 6.0
10 0 0 2 26 2.5 042 4.8 4.8 58 12.6 12.6
11 0 0 27 2.8 2.8 43 4.7 4.7 59 5.9 5.9
12 2.0 2.0 28 4.2 4.2 44 2.33 2.3 60 1.2 1.2
13 2.38 2.38 29 5.0 1.8 45 0 0 61 2.49 2.52
14 0 0 30 01.8 46 3.5 3.5 62 2.43 2.46
15 0 0 31 1.0 1.89 47 3.1 3.2 63 2.37 2.38
16 0 0 32 2.49 2.5 48 2.1 2.1 64 0.39 0.4
PIN NO. REC PB PIN NO. REC PB PIN NO. REC PB PIN NO. REC PB
VOLTAGE CHART

5
TMI (RF101, LGTMI-SLQ1-S)
PIN NO. REC PB PIN NO. REC PB PIN NO. REC PB PIN NO. REC PB
1 0 0 6 3.7 3.7 11 0 0 16 0 0
2 0 4.4 7 0 0 12 4.9 5.0 17 2.3 2.38
35.1 5.1 4 8 0 0 13 0 0 18 0.1 0.2
44.65 4.3 94.8 4.8 14 32.8 32.75 19 1.68 1.7
51.41 1.41 10 4.7 4.74 15 0 0 20 1.58 1.5
VOLTAGE CHART
RESET IC (IC602,BMR-0301G)
REGULATOR IC
(IC802, KA431AZ)
PIN NO. REC PB
15.1 5.1
200
35.0 5.0
PIN NO. REC PB
12.44 2.44
200
34.5 4.5

6
CIRCUIT DIAGRAM
1. POWER SUPPLY SCHEMATIC DIAGRAM

7
CIRCUIT DIAGRAM
2. SERVO/SYSCON/CEC CIRCUIT DIAGRAM(T-DECK)

8
CIRCUIT DIAGRAM
3. VIDEO / AUDIO SCHEMATIC DIAGRAM ( 4 HEAD )

9
CIRCUIT DIAGRAM
4. VIDEO / AUDIO SCHEMATIC DIAGRAM ( HI - FI )

10
CIRCUIT DIAGRAM
5. PIF SCHEMATIC DIAGRAM ( 4 HEAD )

11
CIRCUIT DIAGRAM
6. PIF & MPX SCHEMATIC DIAGRAM ( HI - FI )

12
WAVEFORMS
1. LUMA / CHROMA WAVEFORMS
(IC301-72) 400mVp-p
200mV/10u sec/cm
REC
(IC301-26) 500mVp-p
200mV/10u sec/cm
REC
(IC301-44) 150mVp-p
50mV/10u sec/cm
REC
(IC301-34) 4.2Vp-p
2V/20u sec/cm
REC/PLAY
1
5
7
9
(IC301-74) 380mVp-p
200mV/5u s/cm
PLAY
(IC301-21) 500mVp-p
200mV/10u sec/cm
PLAY
(IC301-44) 150mVp-p
50mV/10u sec/cm
PLAY
(IC301-34) 5.2Vp-p
2V/5msec/cm
Picture search
2
5
7
9
3
(IC301-25) 500mVp-p
200mV/10u sec/cm
REC
6
(IC301-46) 100mVp-p
20mV/10u sec/cm
REC
8
(IC301-35) 2.1Vp-p
1V/10u sec/cm
REC
4
(IC301-25) 500mVp-p
200mV/10u sec/cm
PLAY
6
(IC301-46) 100mVp-p
20mV/10u sec/cm
PLAY
8
(IC301-35) 2.1Vp-p
1V/10u sec/cm
PLAY

13
WAVEFORMS
2. LUMA/CHROMA WAVEFORMS
3. AUDIO WAVEFORMS
(IC301-61) 400mVp-p
200mV/0.5u sec/cm
REC/PLAY
10
(IC301-76) 100mVp-p
20mV/0.5msec/cm
REC
(IC301-100) 120mVp-p
50mV/0.5msec/cm
PLAY
11
15
(IC301-96) 1.5Vp-p
0.5V/0.5msec/cm
REC
(T201-5) 65Vp-p
10V/20u sec/cm
REC
12
16
(IC301-98) 0.45Vp-p
0.2V/0.5msec/cm
REC
13
(T201-6) 75Vp-p
10V/20u sec/cm
REC
17
(IC301-7) 2.3Vp-p
0.5V/0.5msec/cm
REC
14

14
WAVEFORMS
4. SERVO WAVEFORMS
(IC601-18) 5Vp-p
2V/5msec/cm
REC/PLAY
(IC601-97) 4.4Vp-p
1V/5msec/cm
PLAY
(IC601-38) 4.8Vp-p
1V/0.05u sec/cm
REC/PLAY
18
22
26
(IC601-77) 5.5Vp-p
2V/0.2u sec/cm
REC/PLAY
(IC601-89) 1.3Vp-p
0.5V/0.5m sec/cm
REC/PLAY
19
23
(IC601-76) 5Vp-p
2V/0.2u sec/cm
REC/PLAY
20
(IC601-90) 2Vp-p
0.5V/10msec/cm
REC/PLAY
(IC601-87) 2.5Vp-p
1V/0.2msec/cm
REC/PLAY
24
(IC601-94) 3.8Vp-p
2V/5msec/cm
REC
21
25

15
WAVEFORMS
5. Hi-Fi AUDIO WAVEFORMS
(IC251-9,14) 0.8Vp-p
0.2V/0.5msec
EE/REC/PLAY
(IC251-35) 0.75Vp-p
0.2V/0.5msec
EE/REC
27
31
(IC251-16) 0.75Vp-p
0.2V/0.5msec
EE/REC
(IC251-53,57) 0.9Vp-p
0.2V/0.5msec
EE/REC
28
32
(IC251-21) 0.3Vp-p
0.1V/1msec
REC
29 (IC251-29,30) 600mVp-p
200mV/2msec
PLAY
30

16
INSTRUMENT DISASSEMBLY
Perform all disassembly procedures in the order presented. When reassembling,
use the reverse procedure. Make sure that all leads/wiring are routed correctly when reassembling.
1. Top Cover Removal (Fig. 1)
1) Remove two(2) screws Holding the top cover.
2) Carefully lift the back of top cover and slide it to the rear to remove it.

17
INSTRUMENT DISASSEMBLY
2. Front Panel Removal (Fig. 2)
1) Continued from (Fig. 1).
2) Release seven(7) tabs holding the front panel. (Release bottom tabs first)
3) Remove the front panel.

18
INSTRUMENT DISASSEMBLY
3. Deck Assembly Removal (Fig. 3)
1) Remove the top cover, the front panel
2) Disconnect the FPC
3) Remove five(5) screws (A) (B) (C) (D) (E).
4) Remove one(1) screw (F).
5) Pull out the Deck Assembly in the direction of the arrow.

19
INSTRUMENT DISASSEMBLY
4. Main PCB Assembly Removal (Fig. 4)
1) Remove the top cover, the front panel, the bottom cover and the deck assembly.
2) Remove two(2) screws.
3) Release three(3) tabs (A) and lift out the Main PCB in the direction of the arrow.