3-9
ONE POINT REPAIR GUIDE
8. 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.
8-1. NO VCC33, VCC12
8-1-1. Solution
Please check and replace IC505, IC500 on MAIN board.
8-1-2. How to troubleshoot (Countermeasure)
1) Check Voltage of IC505 pin3 on MAIN board.
If IC505 pin3(about 4.9 V) & D500 Input 5.6 VA doesn’t come out, check 5.6 VA from SMPS board.
2) If IC505 pin3(about 4.9 V) is normal, check the PWR_CTRL(IC505 pin2) is high (about 3.3 V)
If PWR_CTRL isn’t high, check pin B2 of IC501 & R524, R522
3) If PWR_CTRL is high, check R524 and if there’s no defective component then replace IC505.
4) If 3.3 V(VCC33) is normal, check 1.2 V output(pin2) voltage of IC500
If 1.2 V of IC500 pin2 doesn’t come out, then replace IC500.
8-1-3. Service hint (Any picture / Remark)
< MAIN board top view >
< MAIN board bottom view >
IC505
IC505
D500
D500
IC500
IC500
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 ...