Daewoo NC-8112E Service Manual page 6

1
Trouble Shooting Guide
MP3/CD Section
2
1. Pick-up unit return
3
AC cord in
Yes
4
Power ON/OFF ON
5
Yes
6
7
Function to CD
and Initializing CD
8
Yes
9
CD open and disc insert
2. CD open and disc insert
CD open and disc
insert
Yes
CD close and cd on
3. Laser diode on
Laser diode on
Yes
Focusing operation
1.Check CN700
2.Check IC701 of 33pin/40pin:3.3V
no
3..Check IC707(MCU IC) of 32pin:(main power on)
1.Check CN704
2.Check IC707(MCU IC) of 23/24/25/26/27/28pin
3.Check IC705 of 5/12/13pin
4. Check CN502,CW504.CN505
5. Check IC504 of 3pin:5.0V
6. Check Q501 collector:+3.3V
7. Check +3.3V (IC500 pin8/18/23/25/38/57/85
no
/113/116/122)
8. Check (IC502 SA5888 of 17pin and 18pin)SP+ 4.41V ,
SP- 3.41V
9. Check SPDO +1.90V (IC500 M5675 pin123)
10. Check (IC502 SA5888 of 12pin and 11pin) SL- 3.81V,
SL+ 3.91V
11. Check CD Board(Around IC solder short,cold soldering )
1. Check CN505 of 5pin.
no
2. Check IC502 SA5888 of 10pin
1. Check CN505 of 3pin.
no
2. Check IC502 SA5888 of 9pin
1. Check +1.8V LD on(HQ500 collector)
2. Check +2.1V (HQ500 base pin) >>>in case of play
no
B
(HQ500)
E
STOP
C 0V
B 3.3V
E 3.3V
C
PLAY
1.8V
2.1V
2.8V
1
2
3
4
5
6
7
8
9