Canon D78-5532, Service Manual, Page: 74 / 119

2.3 IIC Bus D/A Converter ( IC7961, M62393FP) Port Functions
2.4 Output Expander (IC1801, TC74LCX574FT) Port Functions
2.5 Output Expander (IC1802, TC74LCX574FT) Port Functions
Part 4: Troubleshooting
4-12
1 R Reset Fixed “H” I
2 SCL IIC SCL Active “L” I
3 SDA IIC SDA Active “L” I/O
4 AO5 FAN_CON_A O
5 AO6 FAN_CON_B O
6 AO7 FAN_CON_C O
7 AO8 Not used O
8 VrefL D/A converter lower ref. voltage Connected to GND -
9 VrefU1 D/A converter upper ref. voltage (CH5~CH8) Connected to Vcc -
10 GND GND GND -
11 VrefU2 D/A converter upper ref. voltage (CH1~CH4) Connected to Vcc -
12 AO1 Not used O
13 AO2 Not used O
14 AO3 Not used O
15 AO4 Not used O
16 Vcc 5 V Vcc(5V) -
17 Vdd 5 V Vdd(5V) -
18 CS2 Chip Select 2 Fixed “L" I
19 CS1 Chip Select 1 Fixed “L” I
20 CS0 Chip Select 0 Fixed “L” I
Pin No. Name Function Action I/O
1 OE IO_ENB I
2 D0 D0 I
3 D1 D1 I
4 D2 D2 I
5 D3 D3 I
6 D4 D4 I
7 D5 D5 I
8 D6 D6 I
9 D7 D7 I
10 GND GND -
11 CK ADD1_CS Output Port Chip Select Enable = L I
12 Q7 SC_SW SCART and PC2 input switch SCART, PC2 = H O
13 Q6 READY_LED Ready LED Ready = H O
14 Q5 LAMP_LED Lamp Replace LED Replace = H O
15 Q4 TEMP_LED Warning Temperature LED Warning = H O
16 Q3 PWR_LED AC Power LED ON = H O
17 Q2 KO3 KEY Scan Output O
18 Q1 KO2 KEY Scan Output O
19 Q0 KO1 KEY Scan Output O
20 Vdd Power 3.3V -
Pin No. Name Function Name Function Polarity I/O
1 OE IO_ENB I
2 D8 D8 I
3 D9 D9 I
4 D10 D10 I
5 D11 D11 I
6 D12 D12 I
7 D13 D13 I
8 D14 D14 I
9 D15 D15 I
10 GND GND -
11 CK ADD1_CS Output Port Chip Select Enable = L I
12 Q7 -- O
13 Q6 TURBO_ST Strobe for Turbo (IC9401) O
14 Q5 SH_B_ST Strobe for B sample & hold (IC501) O
15 Q4 SH_G_ST Strobe for G sample & hold (IC531) O
16 Q3 SH_R_ST Strobe for R sample & hold (IC561) O
17 Q2 IRM_RS Reset for IC401 O
18 Q1 MCLK_SW Switch for MCLK O
19 Q0 -- O
20 Vdd Power 3.3V -
Pin No. Name Function Name Function Polarity I/O