LG NS9550F Service Manual

3-9
ONE POINT REPAIR GUIDE
NO BOOTING IN CD/USB FUNCTION
After you turn on power key and displayed message in the following order
(HELLO --> VOL XX --> CD or USB) on VFD,
it will not display other message on VFD, and it will not boot-up normally.
4-4. SDRAM (IC502)
4-4-1. Solution
Please check and replace IC502 on MAIN board.
4-4-2. How to troubleshoot (Countermeasure)
1) Check below waveform & soldering status of SDRAM (IC502) on MAIN board.
 If pin17(#CAS), pin18(#RAS), pin19(#CS), pin38(CLK), pin29(address), pin2(DQ) doesn’t come out,
check damping resistor (R568, R506, R570, R544, R547).
2) If resistor is OK, then replace IC502 (SDRAM).
3) After change IC502, if it is still not below waveform, check IC501 (DSP IC).
4-4-3. Service hint (Any picture / Remark)
VCC
Reset
address
data
/CS
RAS
/WE
CAS
IC502
< Signal check point >
< Signal waveform >

LG NS9550F Specifications

General

Brand	LG
Model	NS9550F
Category	Stereo System
Language	English