Text preview for : sr10462b.pdf part of LG sr10462b LG VCR bc-300w sr10462b.pdf



Back to : sr10462b.pdf | Home

2. A/V Circuit Diagram WAVEFORM & VOLTAGE SHEET
_ IC301 Oscilloscope Waveform

X301 is defective.
PB COLOR Signal disappear.




IC301 Pin 20 IC301 Pins 38,32,31 IC301 Pin 28 IC301 Pin 7
PB mode Video in PB/REC mode REC mode
500mvp-p 1Vp-p 4.2Vp-p 1.4Vp-p



13 12




11 8 IC301 Pin 6 IC301 Pin 29 IC301 Pin 41 IC301 Pin 64
IC301 Pin 93 is defective.
Audio Tracking is failed.
REC mode PB mode PB mode PB mode
2.2Vp-p 2.1Vp-p 400mVp-p 600mVp-p

16
7




2

IC301 Pin 23 IC301 Pin 24 IC301 Pins 71 , 72 IC301 Pins 51, 52,54
PB/REC mode PB/REC mode REC mode PB mode
5Vp-p 5Vp-p 340mVp-p 300mVp-p



9
1
2




IC301 Pin 63 IC301 Pin 11 IC301 Pin 10 IC301 Pin 43
PB mode PB mode PB mode PB mode
10 3 6
600mVp-p 3.2Vp-p 1.8Vp-p 400mVp-p
5 4 15 14




IC301 Pin 10 is defective.
_ IC301 Voltage Sheet _ TR Voltage Sheet
PB COLOR Signal disappear.
PIN PB REC PIN PB REC PIN PB REC PIN PB REC PIN PB REC PB mode REC mode
1 2.44 2.42 21 2.41 2.52 41 2.93 2.92 61 3.43 3.43 81 0 0 E C B E C B
2 2.44 2.42 22 0 0 42 3.16 3.14 62 3.31 3.32 82 0.03 0.04 Q301 1.213 3.930 1.864 1.783 3.348 2.435
3 2.46 2.44 23 4.48 4.52 43 3.02 2.05 63 5 5 83 0 0 Q302 1.548 5.158 2.191 1.813 5.147 2.452
4 2.45 2.35 24 4.19 4.23 44 0 0 64 5 5 84 0.03 0.03 Q303 2.161 0 1.499 2.147 0 1.494
5 0.09 0.88 25 1.69 1.69 45 2.34 2.33 65 2.03 2.03 85 0.03 0.03 Q304 1.217 5.061 1.835 1.216 5.039 1.824
6 2.46 2.34 26 0.05 0.06 46 1.46 1.44 66 2.66 2.67 86 0 0 Q305 2.383 0 1.705 2.420 0 1.749
7 2.46 2.34 27 0.34 0.34 47 9.13 9.12 67 3.87 3.86 87 4.87 4.80 Q306 1.222 0 0.545 1.221 0 0.557

Q308, Q309, Q310 8 0 0 28 0.34 0.34 48 1.94 1.96 68 0 0 88 1.83 3.97 Q307 5.258 0.280 5.176 5.186 3.301 4.352

are defective. FL301, Q309, Q311 are defective. Q305 is defective. 9 0 0 29 1.78 1.84 49 0.85 0.85 69 0.80 1.27 89 0 0 Q308 0 0 0.744 15.624 0 -21.49
Q301, 302 are defective.
10 0.93 0.93 30 1.10 4.57 50 0 0 70 1.98 2.92 90 1.83 3.95 Q309 0 0 0.720 -5.69 0 -21.77
No mono Audio Signal Normal Audio signal is not recorded. EE, PB Screen doesn't appear.
PB Screen is bad. 11 1.68 1.68 31 2.97 2.94 51 1.83 1.82 71 2.52 2.51 91 1.83 3.98
in PB MODE. Q310 5.256 5.180 4.583 5.189 -21.64 5.148
IC301 Pin 23, 24 are defective. 12 4.98 2.60 32 - 2.3 52 2.71 2.62 72 3.37 1.73 92 0.02 1.55 Q311 1.224 3.923 1.872 0.271 3.190 0.688
PB and Recording is failed. 13 1.49 1.52 33 1.45 1.37 53 0 0 73 3.8 3.17 93 2.17 0.01 Q3A1 0 5.251 0 1.258 5.179 1.756
(IC301 doesn't operate.) D301 or IC301 Pin30 is defective. 14 1.68 1.38 34 1.81 1.79 54 2.62 2.62 74 1.55 0.01 94 0 2.01
REC Y+C PB Y+C PB AUDIO(MONO)
WAVEFORM REC is failded. 15 2.34 2.32 35 3.25 3.22 55 4.91 4.91 75 4.96 4.94 95 0 0
16 5.01 5.02 36 1.82 1.95 56 0.56 0.57 76 2.43 2.41 96 2.29 2.38
REC Y PB Y REC AUDIO
17 3.08 0.15 37 4.79 4.79 57 3.44 3.44 77 0.01 0.14 97 0 0
REC C PB C 18 1.98 2.45 38 1.81 2.25 58 5.00 5.00 78 2.42 2.42 98 2.43 2.41
19 1.18 2.45 39 4.10 4.10 59 3.36 3.37 79 2.46 2.45 99 5.08 4.28
20 3.01 3.05 40 5.00 5.00 60 3.31 3.31 80 2.43 2.23 100 2.43 2.60



3-32 3-33 3-34