3-11
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.
8-3. SERIAL FLASH (IC503)
8-3-1. Solution
Please check and replace IC503 on MAIN board.
8-3-2. How to troubleshoot (Countermeasure)
1) If the crystal(X500) does oscillate, Check Serial Flash(IC503) on MAIN board.
Check 8pin(VCC), 6pin(CLK), 1pin(CS), 2pin(DO), 5pin(DI) of below waveform.
2) If pin8, 6, 1, 2, 5 doesn’t come out, Check damping resistor(R564, R563, R535, R536, R534) of IC503.
If damping resistor of IC503 is OK, then replace IC503. (it need to download program)
3) After change IC503, if It is still not below waveform, Check IC501(DSP IC).
8-3-3. Service hint (Any picture / Remark)
V
VCC
CLK
DO
CS#
< Signal waveform >
< MAIN board bottom view >
IC503
IC503
Summary of Contents for CM9750
Page 15: ...2 2 ...
Page 19: ...4 SPEAKER SECTION A60L A60R ...
Page 75: ...3 71 3 72 PRINTED CIRCUIT BOARD DIAGRAMS 1 SMPS P C BOARD TOP VIEW ...
Page 77: ...3 75 3 76 2 MAIN P C BOARD TOP VIEW ...
Page 78: ...3 77 3 78 MAIN P C BOARD BOTTOM VIEW ...
Page 79: ...3 79 3 80 3 FRONT P C BOARD TOP VIEW ...
Page 80: ...3 81 3 82 FRONT P C BOARD BOTTOM VIEW ...
Page 81: ...3 83 3 84 4 FRONT_CTRL P C BOARD TOP VIEW BOTTOM VIEW ...