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Copyright © 2018 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ONE POINT REPAIR GUIDE
5. 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.
5-1. SPINDLE MOTOR
5-1-1. Solution
Replace IC400 on MAIN board.
5-1-2. How to troubleshoot (Countermeasure)
1) Check the SPDO signal from pin16 of IC401.
If no signal, check DVCC_3.3V and X400.
2) Check the SPIN+ & SPIN- from IC400 to CN401 for driving SPINDLE motor. It is about 3.6 Vp-p.
If no signal, check M_5 V for IC400.
3) Check if the FFC cable is solidly connected between CN401 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.
5-1-3. Service hint (Any picture/ Remark)
< Waveform of SP- & SP+
for driving SPINDLE motor >
< MAIN board bottom view >
SP+: pin17
SP+: pin17
SP-: pin18
SP-: pin18
IC400
IC400
IC401
IC401
Содержание OK75
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