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There are currently no product reviews.
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Very fast service, best quality of the service manual and the schematics
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This service manual of the old video cassette recorder VT-LC50EM is very good readable even the tiniest numbers (i.e. IC-pins). The circuits are very clear. Many details of the schematic are very good described but in GERMAN language. Many schematic details - but complete at all. Common background information of several details are enclosed and physical knowledge of the TFT liquid crystal display for example. The manual lacks PCB drawings. If you understand german I would recommend this manual for you.
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Hi, this is a very clear manual, nice copy, not quite up to the standard of the very best available but better than many others. I think the price was especially fair for a hard to find manual and I would certainly use this manual seller again. Recommended.
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This schema available for me in good condition. I would highly recommend.
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Thanks for this "hard to find" service manual.
I apreciate the good quality of scanning and the pages scanned in A3 format.
QT-CD141H/161H/162H
� Playback can only be performed when a disc is loaded.
Is the Focus servo active? (Can you hear it working?) No Yes
Check the laser diode driver. Check the area around IC801(16) - (21) (focus servo circuit).
Yes Does the DRF signal change from "L" to "H"? No Yes Yes Is HF waveform normal (see the Fig. 28-1, 2)? Yes Check the tracking system. Waveform is unstable. No
Level is abnormal.
If the disc is not turning, the DRF should not change to "H".
Check the spin system.
Check the periphery of IC801 pins 41 and 42. Yes
w
Check the spin system.
HF 0.1V/DIV 0.5µsec/DIV(DC) IC801 41 (When playing back the disc)
0.5s 1.00 V IC801 16 FD 0.5s 10.0 V IC801 12 CLV+ 0.5s 10.0 V IC801 54 DRF 0.5s 2.00 V IC801 7 TE
Waveform in case of normal playback
2 1 3 4
Figure 28-1 � Check the tracking system.
Check waveform of IC801 pin 7 (TE).
Figure 28-2
The waveform shown in Fig. 28-3 appears, and no-disc state appears soon.
Yes
Tracking servo is inoperative.
Yes
Check the periphery of IC801 pin 8 to pin 15, and IC803 to BI801/CNS801.
Play is possible in TEST mode.
Yes
The unit will be initialzed in Normal mode, but Yes it will not play back.
Normal jump is impeded, and the program top cannot be reached.
Yes
Check the periphery of IC801 pin 14.
Data cannot be read.
Yes
5ms 1.00 V IC801 7 TE
Check the VCO-PLL system.
4
5 ms 5.0 V IC801 54 DRF
3
Figure 28-3 � 28 �
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