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)
V CC
Re set
a ddress
da ta
/ CS
R AS
/ W E
C AS
IC502
< Signal check point >
< Signal waveform >
Содержание CM9550
Страница 15: ...2 2 ...
Страница 19: ...LED SUB LED MAIN A60L A61 A62 651 652 4 SPEAKER SECTION 4 1 FRONT SPEAKER NS9550F LEFT SPEAKER ...
Страница 20: ...LED SUB LED MAIN A60R A61 A62 651 652 FRONT SPEAKER NS9550F RIGHT SPEAKER ...
Страница 21: ...LED SUB LED MAIN A91 A90 952 952 A92 951 4 2 SUBWOOFER SPEAKER NS9550W ...
Страница 61: ...3 40 ...
Страница 81: ...3 79 3 80 3 MAIN P C BOARD TOP VIEW ...
Страница 82: ...3 81 3 82 4 MAIN P C BOARD BOTTOM VIEW ...
Страница 83: ...3 83 3 84 5 FRONT VOLUME MIC PORTABLE P C BOARD TOP VIEW ...
Страница 84: ...3 85 3 86 6 FRONT VOLUME MIC PORTABLE P C BOARD BOTTOM VIEW ...