LG CM4330 Service Manual page 25

4. NO OPERATION OF MD

When no sound output in the CD function, you can not listen to music reading data

from a CD disc if the servo motors in MD don't work. This step is for checking the

SPINDLE MOTOR among them.

4-1. SPINDLE MOTOR

4-1-1. Solution

Please check and replace IC301, IC302 on MAIN board.

4-1-2. How to troubleshoot (Countermeasure)

1) Check the SPDO signal from pin16 of IC302.

If no signal, check 3.3 V(RF) and X301.

2) Check the SPIN- & SPIN+ from IC301 to CN303 for driving SPINDLE motor. It is about 3.6 Vp-p.

If no signal, check +1.8 V and +5 V for IC301.

3) Check if the FFC cable is solidly connected between CN303 and MD.

4) Check the MD.

If the spindle motor is sort-circuit or has any trouble, it can not rotate CD discs.

Please check the function after changing another MD.

4-1-3. Service hint (Any picture / Remark)

< Waveform of SP- & SP+

for driving SPINDLE motor >

ONE POINT REPAIR GUIDE

About 3.6Vpp

Sp-

Pin18 to CN303

< Signal check point >

3-6

IC301

Sp+

Pin17 to CN303