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CD-C621H
TROUBLESHOOTING (CD SECTION)
When the CD does not function
When the CD section does not operate When the objective lens of the optical pickup is dirty,this section may not operate.Clean the objective lens,and check the playback operation.When this section does not operate even after the above step is taken,check the following items. Remove the cabinet and follow the troubleshooting instructions. "Track skipping and/or no TOC (Table Of Contents) may be caused by build up of dust other foreign matter on the laser pickup lens. Before attempting any adjustment make certain that the lens is clean. If not, clean it as mentioned below." Turn the power off. Gently clean the lens with a lens cleaning tissue and a small amount of isopropyl alcohol. Do not touch the lens with the bare hand. Dust gradually accumulates on the objective lens during use, and it may degrade performance. To avoid this problem, use a cleaning disc designed for CD optical pickup lenses.
HOW TO USE 1. Using the brush in the cleaner cap, apply 1 or 2 drops of the cleaning fluid to the brush on the CD cleaner disc which has the mark next to it. 2. Place the CD cleaner disc onto the CD disc tray with the brush side down, then press the play button. 3. You will hear musicfor about 20 seconds and the CD player will automatically stop. If it continues to turn, press the stop button. CAUTION The CD lens cleaner should be effective for 30 - 50 operations, however if the brushes become worn out earlier then please replace the cleaner disc. If the CD cleaner brushes become very wet then wipe off any excess fluid with a soft cloth. Do not drink the cleaner fluid or allow it to come in contact with the eyes. in the event of this happening then drink and / or rinse with clean water and seek medical advice. The CD cleaner disc must not be used on car CD player or on computer CD ROM drives. All rights reserved. Unauthorized duplicating, broadcasting and renting product is prohibited by law.
Cleaner Liquid
Cleaning Disc PARTS CODE: UDSKA0004AFZZ
Figure 38
38
CD-C621H
· When the turntable fails to stop.
5V Is from 2.5V 0V
5 V till 2.5V down pulse (approx. 300 ms)
No
input into the IC701 pin 21 when the turntable is rotating?
Check the SWM3 and the wiring from the IC701 pin 21 to the SWM3.
Yes Is there following voltage input on the IC701 pin 21 in the specific state? When the CD mechanism is moved up: 0V In other states: 4.3V Yes Check IC2 pin26 Q91 and Q93 and the periphery.
No
Check the MECHA UP SW and the wiring from the IC701 pin 21 to the MECHA UP SW.
Yes IC701 defective.
· When turntable fails to move.
Is there following voltage input on the IC701 pin 21 in the specific state? When the CD mechanism is moved up: 0V In other states: 4.3V
No
Check the MECHA UP SW and the wiring from the IC701 pin 21 to the MECHA UP SW.
Yes
Is L output from the IC2 pin 26 during SEC when the disc skip switch is pressed?
Check the wiring of IC2 pin 26 and Q93 pin 2. No OK
Yes IC2 defective. Is 4V output from the Q91 emitter during operation stated above? Yes Check Q91, Q93 and the periphery.
No
Check turntable motor and turntable mechanism.
39
CD-C621H
· When the CD tray fails to open or close.
Is there following voltage input in specific state of IC701 pin 19? Open state: 0V Close state: 0V Intermediate state between open state and close state: 4.3V Yes Is H output to IC2 pin 24 or 25 for 7 seconds when the OPEN/ CLOSE key is pressed?IC91 is defective. Replace it. Check the wiring of the IC2 pins 24 and 25, IC91 pins 1 and 3. No OK Yes IC2 defective. No Check the OPEN CLOSE SW and the wiring from the IC701 pin 19 to the OPEN CLOSE SW.
Is 4V output between IC91 pins 3 and 7 during operation stated above?
Check the periphery of IC91. No OK
Yes Check the loading motor (M1) and the loading mechanism.
IC91 defective.
· The CD function will not work.
The CD operating keys don't work. Yes Check the CD, DSP, power supply, and 16.93 MHz clock, and reset terminal. Yes Check the waveform of SCK, SO (DATA) and SI (COMM). Yes See if the pick-up is in the pick-up in PICKUP IN SW position. Yes If the items mentioned above are OK, check the main microcomputer IC701.
0.5s 0.50 V IC1 16 FD
Focus search is performed two times when play operation is done without disc.
· The CD operating keys work.
Check the Focus - HF system. Playback can be performed without a disc. Yes Does the pick-up move up and down twice? Yes No Does the output waveform of IC1(16)(FD) match that shown in Fig. 40? No Check the IC1(50)(CLK) line, 4MHz. Check the microcomputer data on pins (51)(CL), (52)(DAT) and (53)CE. Focus search OK
0.5s 0.50 V IC1 7 TE 1 2
Figure 40
Check the area around IC5-CNP2. Yes
40
CD-C621H
· Playback can only be performed when a disc is loaded.
Is the Focus servo active? (Can you hear it working?) Yes Yes Does the DRF signal change from "L" to "H"? No Yes Yes Is HF waveform normal (see the Fig.41-1, 2)? Yes Check the tracking system. Waveform is unstable. No Level is abnormal. Yes Check the spin system.
Waveform in case of normal play-back
No
Check the laser diode driver. Check the area around IC1(16) - (21) (focus servo circuit).
If the disc is not turning, the DRF should not change to "H".
Check the spin system.
Check the periphery of IC1 pins 41 and 42.
HF 1.0V/DIV 0.5µsec/DIV(DC) (When playing back the disc)
0.5s 1.00 V IC1 16 FD 0.5s 10.0 V IC2 13 CLV+ 0.5s 10.0 V IC1 54 DRF 0.5s 2.00 V IC1 7 TE
2 1 3 4
Figure 41-1 · Check the tracking system.
Figure 41-2
Check waveform of IC1 pin 7 (TE). Check the periphery of IC 1 pin 8 to pin 15, and IC 5 to CNP2.
The waveform shown in Fig.41-3 appears, and nodisc state appears soon.
Yes
Tracking servo is inoperative. Yes
Play is possible in TEST mode.
Yes
Although IL is possible, play is impossible.
Yes
Normal jump is impeded, and the program top cannot be reached.
Yes
Check the periphery of IC 1 pin 14.
Data cannot be read.
Yes
Check the VCO-PLL system.
5ms 1.00 V IC1 7 TE
4
5 ms 5.0 V IC1 54 DRF
3
Figure 41-3 41
CD-C621H
· Checking the spin system.
Play operation is performed without disc. Yes The turntable rotates a little. No The turntable fails to rotate or rotates at high speed. Yes Check the periphery of IC1 pins 23 to 27, pin 39, and pin 40, IC2 pin 12 and pin 13, IC5 to CNP3. Yes The spin driver circuit is normal.
· Checking the VCO-PLL system
Play operation is performed when disc exits. Yes Although HF waveform is normal, TOC data cannot be read. Yes
Check PDO waveform (Fig. 42). Abnormal Check the IC1 pins 43 and 44, IC2 pins 3, 5, 7, 10, and 11.
Stop --> Play As VCO frequency is locked at 4.32 M Hz, voltage of PDO rises and stabili- zes.
2
0.5s 1.00 V IC2 3 PDO 0.5s 1.00 V IC2 16 FD
3
Figure 42
· Although HF waveform is normal and the time indication is normal, no sound is emitted.
No
Check IC 2 pin 48 (EFLG). Yes Check IC2 pins 37, 40. Abnomal Check IC 401 and POWER AMP IC 801.
Usually, the number of pulses of flawless disc is 100 pulses/sec or less.
42