Trouble Shooting; Vfd Dosen't Light - Denon RCD-M39 Service Manual

TROUBLE SHOOTING

1. VFD dosen't light

Check Power Supply Voltages for System µ-com.
MCU_CD B'D
• ST+3.9V, [PMSN] : 1pin
• [D109] cathode
Check Reset signal for System µ-com.
MCU_CD B'D
• [IC11] : 82pin RESET
"H" level O.K.?
Check Oscillation waveform.
MCU_CD_B'D
• [IC11] : 72pin
10MHz OK?
Check Power On Signal.
MCU_CD B'D
• [IC11]:86pin P_DWN
"H" level OK?
Check Power Supply Voltages for VFD.
FRONT B'D
• [FL81] : 38pin HV
• [FL81] : 37pin VDD
• [FL81] : 1pin F1-43pin F2
Check Reset Signal for VFD.
FRONT B'D
• [FL81] : 35pin/RST
"H" level O.K.?
Check VFD dirive Signal.
FRONT B'D
• [FL81] : 32,33,34pin DA,CP,CS
END
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OK
OK
OK
OK
OK
OK
NG
Check Soldering.
• [PMSN] : 1pin
• SUB TRANS B'D
NG
Check Soldering.
• [IC11] on MCU_CD B'D
NG
Check Soldering.
• [X101] on MCU_CD B'D
NG Check Soldering.
• [PMMO] : 2pin on MCU_CD B'D
• SUB TRANS B'D
Check Soldering.
• FRONT B'D [CBFJ] : 3pin +VKK
• FRONT B'D [CBFJ] : 2pin FL1 / 1pin FL2
• FRONT B'D [FCFA] : 1pin VFD+3.3V
NG
• POWER B'D [CBSK] : 2pin FL1 / 1pin FL2
• POWER B'D [CBSK] : 3pin VFD3.3V
• MCU_CD B'D [FCMA] : 1pin VFD+3.3V
Check Parts
• POWER B'D
Q909,D910,D909,D911,D912 OK?
Check Soldering.
NG
• FRONT B'D [FCFA] : 3pin VFD_RST
• MCU_CD B'D [FCMA] : 3pin VFD_RST
• [IC11] on MCU_CD B'D
Check Soldering.
• FRONT B'D [FCFA] : 4,5,6pin
NG
VFD_CE,VFD_CLK,VFD_DI
• MCU_CD B'D [FCMA] : 4,5,6pin
VFD_CE,VFD_CLK,VFD_DI
• [IC11] on MCU_CD B'D
45