Zenith D35, Service Manual

Page: 15 / 156

3-3
ELECTRICAL TROUBLESHOOTING GUIDE
1. Power(SMPS) CIRCUIT
NO 5.3VA.
Replace the F101.
(Use the same Fuse)
Is the F101 normal?
Is the TH101
normal?
Is the BD101
normal?
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
Replace the
BD101.
Replace the TH101.
Is the D105
normal?
Check or Replace
the D105.
Replace the D129.
Replace the IC106.
Replace the D127.
Replace the D126.
Replace the D125.
Replace the D124.
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
Is Vcc(12~28V) sup-
plied to IC104 Pin3?
Is the D129 nor-
mal?
Is there about 2.5V
at the IC106 Vref?
Is the D127
normal?
Is the D126
normal?
Is the D125
normal?
Is the D124
normal?
Check the Main PCB
Power supply Line short?
(1) No 5.3VA (SYS/Hi-Fi/TUNER)
NO 5.0VA.
Check or Replace
the D129. Is there about 5.3V
at the IC152 Pin1?
Check or Replace
the IC152.
NO
YES
YES
(2) No 5.0VA
NO 3.3VA.
Check or Replace
the D127. Is there about 3.8V
at the IC152 Pin1?
Check or Replace
the IC151.
NO
YES
YES
(3) No 3.3VA
NO 12VA.
Check or Replace
the D126. Is there about 13V
at the IC153 Pin1?
Check or Replace
the IC153.
NO
YES
YES
(4) No 12VA
NO
NO
NO
NO
NO