3-10
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.
8-2. CRYSTAL (X500)
8-2-1. Solution
Replace X500 on MAIN board.
8-2-2. How to troubleshoot (Countermeasure)
1) If 3.3 V & 1.2 V is normal, Check the CHIP_RESET of IC501 pin T12 on MAIN board.
If CHIP_RESET isn’t high, Check MICOM(IC101) pin40.
2) If CHIP_RESET is high, Check the soldering status of 24 MHz crystal (X500).
3) If the crystal (X500) doesn’t oscillate, Check R508, R509, C502, C503 around crystal (X500).
If there’s no defective component, then replace X500.
8-2-3. Service hint (Any picture / Remark)
X
X
XII
X
XO
O
X500
< Signal waveform >
< MAIN board top view >
IC501
IC501
X500
X500
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 ...