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Only for training and service purposes.
ELECTRICAL TROUBLESHOOTING GUIDE
USB PART
Refer to Power Part Troubleshooting
Check JK501 1pin Voltage 5.1 V
YES
Check FB306 Voltage 5.1 V
Check IC306
Check JK501 pin2(D-), pin3(D+)
Replace Main PCB
YES
NO
Check Reading OK
IC501 pin35, pin36
YES
YES
NO
NO
OK
3. USB FUNCTION