FUNAI LT8-M40BB - Troubleshooting Flowchart 9: AL+5 V Output Issue; Troubleshooting Flowchart 10: P-ON+3.3 V Output Issue; Troubleshooting Flowchart 11: P-ON+9 V Output Issue; Troubleshooting Flowchart 12: Key Operation Failure

8-3 A03P0TR
AL+5V is not output.
FLOW CHART NO.9
Is approximately 5V voltage supplied to the cathode
of D523?
Check if there is any leak or short-circuit on the
loaded circuit, and service it if defective.
Ye s
Check D523, D524, C515 and their periphery circuit,
and service it if defective.
No
P-ON+9V is not output.
FLOW CHART NO.11
Ye s
No
Is approximately 13V voltage supp
lied to the
collector of Q517?
Is approximately 10V voltage supplied to the
base of Q517?
No
Ye s
Replace Q517.
Replace Q510.
P-ON+3.3V is not output.
FLOW CHART NO.10
Is approximately
5V voltage supp
lied to the collector
of Q510?
Ye s
Check D523, D524, C515 and their per
iphery circuit,
and service it if defective.
Check D539, C522 and their periphery circuit, and
service it if defective.
Check Q508, Q520, D541, D
542, P-ON-H2 line and
their per
iphery circuit, and service it if defective.
No
Is approximately 3.4V voltage supplied to the base
of Q510?
Ye s
Check Q508, Q511, D526, P-ON-H2 line and their
peripher
y circuit, and service it if defec
tive.
No
When pressing each switches (SW101B, SW103B-
SW107B) do the voltage of Pin(11) on C
N403
increase?
Ye s
No
FLOW CHART NO.12
Are the contact point and installation state of the key
switches (SW101B, SW103B-SW107B) normal?
Re-install the switches (SW101B, SW103B-SW107B)
correctly or replace the poor switch.
No
Check the switches (SW101B, SW103B-SW107B)
and their periphery, and service it if defective.
Ye s
Replace Digital Main CBA Unit.
The key operation is not functioning.