System Control Path - NAD M3 Service Manual

3. SYSTEM CONTROL PATH

MCU
AT89C51
P0.0
P0.1
P0.2
P0.3
P0.4
P0.5
P0.6
P0.7
P1.0
P1.1
P1.2
P1.3
P1.4
P1.5
P1.6
P1.7
P2.0
P2.1
P2.2
P2.3
P2.4
P2.5
P2.6
P2.7
P3.0
U83 MAX3221 (FPP)
P3.1
P3.2
Q85 Q86 (FPP)
P3.3
P3.4 Q89 inverter(FPP)
P3.5 Q91 (PSU)
P3.6
U84 U85 7400 (FPP)
P3.7
P4.0 U108 U113 U208 U213
P4.1 CD4094 (PRE)
P4.2
U110 U210 (PRE)
P4.3
CD4094
P4.4
P4.5
P4.6 U105 (PRE) TC9274
P4.7
P5.0
P5.1 U205 (PRE) TC9274
P5.2
U109 U209 (PRE)
TC9274
P5.3
U109 U209 (PRE)
P5.4
TC9274
P5.5
P5.6 RL301 RL302 RL401 RL402
P5.7 OUTPUT RELAYS (LAMP/RAMP)
ENCODE
VFD
EEPROM
KEYS
RJ45 RS232 SOCKET (REAR PANEL)
IR IN/OUT SOCKET ( REAR PANEL)
Protect Circuit (High when Protect)
OP91 OPTOISO (PSU) RL91 standby relay (PSU)
D81 Tri-color LED (FPP)
RL101 ... RL112, RL201 ... RL212
For Input Select and Biamp Filter Switch
Q130 Q131 Q230 Q231 for Mute
U104 U107 U204 U207 (PRE) MAX4621
30dB Attenuator, Q101...Q103, Q201...Q203,
6.5 Gain/ 0.5 Gain Switch
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