Sharp VC-A565U, Руководство по обслуживанию

Страница: 38 / 78

38
VC-A565U/H965U
7.
TR
OUBLESHOO
TING
FLOW CHART NO.1
No power
The fuse blows out even when it is replaced with new one. See
FLOW CHART NO.2
<Fuse blown out.>.
YES
YES
YES YES
NO NO
NO NO NO
Is the fuse good?
Is the normal state restored when once unplugged power cord is plugged again after several seconds?
Check for leak or short-circuiting of primary circuit part. (L901, D901~904, T901, C906, R904, Q901~902, etc.)
Are AT 5V voltage line normal?
Are AT 44V, AT 27V, PC 12V, normal?
Check each rectifier circuits and short-circuit of secondary circuit.
Is "H" level applied at pin(76) of IC701?
Check the power failure circuit. (Q705)
FLOW CHART NO.3
When the output voltage fluctuates.
Check whether the secondary side photocoupler circuit operates normally.
Check the circuit and replace parts. (IC901, IC903, etc.)
NO
YES
Check whether the primary side photocoupler output control functions normally.
Check the circuit and replace parts. (IC901, IC903, Q902, T901, etc.)
NO
YES
Replace IC901.
FLOW CHART NO.2
Fuse blown out.
Case (1)
Case (2)
Check for leak or short-circuiting of primary circuit part. (L901, D901~904, T901, C906, R904, Q901~902, etc.)
Check for short-circuiting of rectifying diode and circuit in each rectifying circuit of secondary circuit. (D9334, D931~933)
FLOW CHART NO.4
When buzz is heard from the vicinity of power circuit.
Check for short-circuiting of circuit and rectifying diode of each rectifying circuit of secondary circuit and check for failure of shunt regulator circuit. (D9334, D931~933, IC903, C935, C963)