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3-6

Only for training and service purposes.

ONE POINT REPAIR GUIDE

4. 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.

4-1. NO DVCC_3.3V, 1.2 VA

4-1-1. Solution

Please check and replace IC202, IC205 on MAIN board.

4-1-2. How to troubleshoot (Countermeasure)

1) Check Voltage of IC202 pin3 on MAIN board.



If IC202 pin3 (about 3.3 V) & pin1 Input 5.1 VA doesn’t come out, check IC201 & +12 V from SMPS board.

2) If IC201 pin2 (about 5.1 V) is normal, check voltage of IC205 pin3 (about 1.2 VA).

If IC205 pin3 (about 1.2 VA) doesn’t come out, check R218, R219, R221.

If there’s no defective component then replace IC205.

3) PWR_CTRL is high, check R214, R233 and if there’s no defective component then check DVCC_3.3V

short with GND.

PWR_CTRL (IC204 pin3) is high (about 3.2 V)

 If PWR_CTRL isn’t high, check pin D11 of IC501 & R512, R513

4) If PWR_CTRL is high, check R5B78 and if there’s no defective component then replace IC204.

4-1-3. Service hint (Any picture/ Remark)

< MAIN board top view >

< MAIN board bottom view >

IC204

IC202

IC205

IC203

IC201

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