Yamaha EMX5016CF Service Manual page 5

EMX5016CF
3-2 Repair Flowchart
Check the primary side circuit.
Note: Check and repair must be done carefully, otherwise the electrical shock may be caused.
Discharge (*1)
1
Check R418 and R424 resistor value.
2
Check Q406 and Q407 C-E resistor value.
3
Check R419 and R421 resistor value.
4
Check R429, R430, R453 and R454
resistor value.
(Secondary)
*1) To prevent the electrical shock, be sure to discharge electricity from the capacitor.
Discharge is not necessary if you have left the unit for 10 minutes or more after turning the power off.
112
START
Turn the power off.
(Disconnect AC plug from the wall outlet.)
Between ± terminals of C409 and C410
Between CN405 and CN409
Between CN406 and CN408
R418, R424 = 6.8 Ω?
YES
Q406, Q407 C-E
Resistor value = 0 to several Ω?
NO
R419, R421 = 33 Ω?
YES
R429, R430, R453, R454 = 1 Ω?
YES
A
NO
Replace R418 and R424.
YES
Replace Q406 or Q407.
Replace IC402.
NO
R419, R421
OPEN or SHORT?
Replace R419 and R421.
Replace D404 and D405.
NO
Replace R429, R430, R453 and R454.
SHORT
OPEN