LG CM9750 Service Manual

3-8
ONE POINT REPAIR GUIDE
7. SPEAKER NO AUDIO
Speaker No Audio
7-1. AMP IC (IC700~IC705)
7-1-1. Solution
Replace IC700~IC705 on MAIN board.
7-1-2. How to troubleshoot (Countermeasure)
1) Check supply voltage of AMP(CN110) & PWM signal
Normal supply voltage and signal  Check AMP IC.
Poor supply voltage  Check SMPS Assy.
Poor signal  Check PWM IC.
2) Check CSD of FET driver IC (IRS2092 : EAN60778301).
CSD has about 5 V on normal state.
When AMP has problem, CSD is LOW state or keep change LOW to HIGH.
7-1-3. Service hint (Any picture / Remark)
< MAIN board top view >
< MAIN board top view > < MAIN - AMP circuit >
CN110
CN110
pin1, 2 : +58 V
pin1, 2 : +58 V
pin3, 4 : PGND
pin3, 4 : PGND
pin5, 6 : -58 V
pin5, 6 : -58 V
pin5 of IC700
pin5 of IC700


CSD
CSD

LG CM9750 Specifications

General

Type	-
Cassette deck	No
Product color	Black
Number of decks	1 deck(s)
Disc loading type	Tray
Optical disc player	Yes
Number of optical discs	1 discs
Speaker type	3-way
RMS rated power	- W
Woofer diameter	304.8 mm
Tweeter diameter	25.4 mm
Number of speakers	2
Mid-range driver diameter	165.1 mm
Subwoofer driver diameter (imperial)	12 \
Tuner type	Digital
FM band range	87.5 - 108 MHz
Supported radio bands	FM
Headphone connectivity	3.5 mm
USB 2.0 ports quantity	USB 2.0 ports have a data transmission speed of 480 Mbps, and are backwards compatible with USB 1.1 ports. You can connect all kinds of peripheral devices to them.
Microphone connectivity	6.3 mm
Apple docking compatibility	Not supported
Disc types supported	CD, CD-R, CD-RW
Playback disc formats	CD audio
Audio formats supported	MP3, WMA
Volume control	Rotary
Equalizer modes	Bass, Classic, Jazz, Pop, Rock
Power source	AC

Weight and Dimensions

Main unit weight	6600 g
Main unit dimensions (WxDxH)	450 x 355 x 160 mm