Troubleshooting - Harman Kardon AVR-134 Service Manual

Symptom
Power On Failure
1. FLT does not light up.
2. STANDBY LED does not light
up.
Fuse Disconnection. (Power On)
Key Disorder.
Power Off in 2~3 sec. after Power
On.
Bump Sound
(During input­select switch's
change.)

TROUBLESHOOTING

Cause and Remedy
A) AC­Cord check.
B) PowerTrans (Main/Standby) check.
C) Fuse's disconnection check.
D) Connector's disconnection or disjuction.
Change or close insertion of the connector.
E) Inferior Standby switch.
F) VFD Driver I.C & Resonator check.
1. VFD Driver I.C & Resonator check.
2. VFD Driver clock pulse check.
A) Inferior transfomer.
B) AMP drive TR out. (POWER TR)
C) AMP drive TR out. (POWER TR)
D) Voltage check.
1. B+(47V)V, B­(47)V
A) Key's being pushed check.
B) Key signal input components inferior.
C) Key PORT check.
D) μ­COM I.C inferior
1. μ­COM I.C VCC +3.3V check.
A) Regulator I.C out.
1. Signal IN/OUT check.
B) Drive transistor out.(POWER TR)
C) Protection circuit check.
1. Output DC check.
2. μ­COM I.C protection terminal check.
D) Connector's disconnection or disjunction.
E) SLEEP MODE cancellation.
A) FRONT Mute transistor's out and inferior.
μ­COM front mute control PORT check.
B) CENTER Mute transistor's out and inferior.
μ­COM center mute control PORT check.
C) SURROUND Mute transistor's out and inferior.
μ­COM surround mute control PORT check.
22
Ref No.
F (301)
CN301, FPC101
SW(700)
I.C701 SC16315
I.C701 Pin No13
I.C701 Pin No5
Q206(FL, FR, C, SL, SR)
Q205(FL, FR, C, SL, SR)
I.C101 Pin No. (49, 50, 51)
I.C101 Pin No. (49, 50, 51)
I.C300 (LM1117S_3.3V)
Q205(FL, FR, C, SL, SR)
Q206(FL, FR, C, SL, SR)
μ­COM Pin No.(1)
CP(111)
Q(105)
I.C101 Pin No. (28)
Q(107)
I.C101 Pin No. (26)
Q(109)
I.C101 Pin No. (27)