Yamaha XP7000, Руководство по обслуживанию

Страница: 50 / 92

XP7000/XP5000
50
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)
Check R410 and R411 resistor value.
NO
YES
2
Check Q406 and Q407 C-E resistor value.
NO
YES
3
Check R421 and R422 resistor value.
NO SHORT
YES OPEN
4
Check R420 resistor value.
NO
YES
5
Check R431 and R432 resistor value.
(Secondary)
NO
YES
*
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.
R421, R422 = 10 ohms?
R431, R432 = 2.2 ohms?
Replace R431 and R432.
Replace R420.
Replace R410 and R411.
Replace R421 and R422.
Replace D409 and D410.
Replace Q406 or Q407.
Replace IC402.
R421, R422
OPEN or SHORT?
START
Between
±
terminals of C420 and C421
Between W406-W407, W407-W408
Between terminals of C402
A
R420 = 4.7 ohms?
Q406, Q407 C-E
Resistor value
≠
0 to several ohms?
R410, R411 = 6.8 ohms?
Turn the power off.
(Disconnect AC plug from the wall outlet.)
1
(0 to several ohms)