Flow Chart No.3; Flow Chart No.4 - Denon DCD-F109 Service Manual

FLOW CHART NO.3

The fluorescent display tube does not light up.
Is +3.3V_D voltage supplied to Pins(37) of FLT500?
YES
Is the voltage of approximately +42V supplied to Pin(38) of FLT500?
YES
Is the voltage of approximately +3.3V(AC) supplied to Pin(1)-Pin(43)
of FLT500?
YES
Check the fluorescent display tube control signal of ab microcomputer.
(FL_RST,FL_CS,FL_CLK,FL_MDT)

FLOW CHART NO.4

The key operation is not functioning.
Are the contact point and the installation state of the key switches
(S500-506) normal?
YES
When pressing each switches (S500-506), do the voltage of pin
(4),(5),(6),(99),(100) of IC11 decrease?
YES
Replace IC11.
NO
Check the +3.3V_D line and service it if defective.
NO
Check D619,D620,ZD605,ZD606,Q608 and the periphery
circuit, and service it if defective.
NO
Check the FL1/FL2 line and service it if defective.
NO
Re-install the switches (S500-506) correctly or replace
the poor switch.
NO
Check the switches (S500-506) and their periphery, and
service it if detective.
36