36
VC-AA350A/L/M/W
VC-AA352W,AA360A,AA370A
VC-AA550A/L/W,AA560A,AA570A
FLOW CHART NO.1 POWER TROUBLESHOOTING(1)
No power
Unplug the AC power cord.
Replug it a few minutes later.
See FLOW CHART NO.2 POWER
TROUBLESHOOTING(2)
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
Is the fuse good?
Replace fuse.
Is AT 5V voltage line normal?
Check primary circuit.
Are AT 45V, AT 24V and AT 12V lines
normal?
Check each rectifier circuits and
short-circuit of secondary circuit.
Is "H" level applied at pin(1) of
IC701?
Check peripheral circuits of Q706
and P-FAIL (L) signal line etc.
Check system control circuit(IC701).
7. TROUBLESHOOTING
FLOW CHART NO.3 POWER TROUBLESHOOTING(3)
In case of abnormal noise(sound)
Check D931, D932, D933 and
D934.
Check D931, D932, D933 and
D934. Replace where necessary.
NO
FLOW CHART NO.4 POWER TROUBLESHOOTING(4)
No power is turned on
Does power control (H) signal at pin
(96) of IC701 change from "L" to "H"
level?
Check IC701.
YES
YES
YES
NO
NO
NO
Does the base of Q967 change from
about 5.0V to 2.5V?
Check IC701 and all the way up
through to Q967.
Is voltage of 5V sent out the
collector of Q967.
Check peripheral circuit of Q967
and PC 5V line.
Check peripheral circuit for poor
soldering.
YES
YES
NO
NO
FLOW CHART NO.5 POWER TROUBLESHOOTING(5)
In case of output voltage at low level.
Check peripheral circuits IC901, IC903,
C9336, R932, R935, R930 and R931.
From checking result IC901, IC903, C9336, R932,
R935 , R930 and R931. Replace where necessary.
Check short-circuit or leakage of T901.
Replace T901.
Check primary circuit and peripheral
circuit of Q901.
FLOW CHART NO.2 POWER TROUBLESHOOTING(2)
In case of Fuse(F901) blown out.
Replace F901, Q901, IC902 and
R904, check D901, D902, D903 and
D904. Replace where necessary.
Check short-circuit or leak of D931,
D932, D933, D934, and secondary
circuit.