3-11
ELECTRICAL TROUBLESHOOTING GUIDE
2. POWER CHECK FLOW
No 3.3 VA
Check 5 VA troubleshooting flow
YES
YES
NO
Replace IC605 or check output circuits
Is the 5 VA on
pin3 of IC605?
Check voltage reference pin1 of IC605
YES
NO
Is the 3.3 V on
pin2 of IC605?
No 5 V USB
Check 5 VA troubleshooting flow
YES
YES
NO
Replace Q601 or check output circuits
Is the 5VA on
collector of IQ605?
Check voltage on base of Q601 or ZD601
YES
NO
Is the 5V on
emitter of IQ605?
No 5 V
Check 5 VA troubleshooting flow
YES
YES
NO
Replace Q601 or check output circuits
Is the 5 VA on
collector of IQ601?
Check voltage on base of Q601 or ZD601
YES
NO
Is the 5V on
emitter of IQ601?
jomi