Kenwood KDC-X679 Service Manual page 4

KDC-X679
Ref. No. Application / Function
Q10,11 SERVO+B AVR (Panel Mecha)
Q12 SW for IC7
Q13,15,16 FL&ILL AVR
Q17,18 AUDIO 10.5V AVR
Q19~21 Pre-Amp -9V AVR
Q22~24 Pre-Amp +9V AVR
Q25,26 P-ANT SW
Q27,30 P-CON SW
Q28,29 P-CON Protection
Q31 Ex Amp Control Buffer
Q32 Small lamp det SW
Q33,34 SERGE Det.
Q35 BU det
Q36 ACC det
Q37,38 Pre-out mute driver
Q39 Sub-out mute driver
Q40 AC-out mute driver
Q41,42 AM+B SW
Q44 DSI Driver
Q45,46 Panel 5V SW
Q47~52 Pre-out mute SW
Q56,57 AC-out mute SW
Q58,59 Sub-out mute SW
Q60 Level meter mute SW
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COMPONENTS DESCRIPTION
When Q10'base goes Hi, S+B AVR outputs 8.5V.
When Q12'base gose Lo, IC7 is turned on.
When Q13'2pin goes Hi, ILL AVR outputs 10.5V.
When Q16'base goes Hi, AVR outputs 10.5V.
Q19 and 21 works as a differential amplifier, Q20 works as a driver and -9.1V is supplied
to OP Amp for Pre-out.
Q22 and 24 works as a differential amplifier, Q23 works as a driver and +9.4V is supplied
to OP Amp for Pre-out.
When Q23'base goes Hi, P-ANT SW outputs 14V.
When Q30'base goes Hi, AVR outputs 14V.
Protect Q27 by turning on when P-CON output is grounded.
When Q32'base goes Hi, Q32 is turned on.
When Q33'base goes Hi, IC4 is changed into a standby state.
When Q35'base gose Hi, Q27 is turned on.
When Q36'base gose Hi, Q29 is turned on.
When a base gose Lo, mute driver is turned on.
When a base gose Lo, mute driver is turned on.
When a base gose Lo, mute driver is turned on.
When Q42'base gose Hi, AM+B is out.
DSI lights when the base is "L".
DSI turns off when the base is "H".
DSI turns on and off when panel is taken off.
When Q46'base gose Hi, PANEL 5V is out.
When a base gose Hi, Pre-out is muted.
When a base gose Hi, AC-out is muted.
When a base gose Hi, Sub-out is muted.
When a base gose Hi, Level meter is muted.
Operation / Condition / Compatibility