Bosch HBL 73 Service Manual page 50

ELETTRODOMESTICI
VIA CHECCHI 98
I 21013 GALLARATE
ITALY
THE FOLLOWING TABLES PROVIDE INFORMATION ABOUT EACH LINE IN THE PIN-TO-PIN CABLES CONNECTING THE
ELECTRONIC BOARDS. SOMETIMES THE ELECTRONIC BOARDS ARE CHARGED WITH BEING RESPONSIBLE FOR MANY
FAULTS WHEN ACTUALLY THEY ARE CAUSED BY BAD CONNECTIONS. BEFORE REPLACING THE BOARDS, CHECK THE
HARNESS, THE CONNECTORS AND THEIR TERMINALS. CHECK THE TABLES TO SEE IF THE FAULT DETECTED CAN BE
DUE TO A WRONG CONNECTION.
Examples:
1. [LIGHT], [TEMPERATURE], [COOKING MODE] keys are not working. In the table describing the cable between display board
and keyboard, see that line 2 is the only one shared by these keys. Check the corresponding wire and its terminal in the
connector before replacing the electronic boards.
2. The VFD display never turns on. Check pins 1,2,3 on the cable between Power and Display Boards.
3. The buzzer doesn't beep. Check pin 4 wire and terminals of P1A cable.
CONNECTION CABLE BETWEEN POWER AND DISPLAY BOARD - P1A (8POS)
PIN FUNCTION
1 FILAMENT 1
2 +HV
3 FILAMENT 2
4 +15V
5 +5V
6 GND
7 GND
8 GND
Tuesday, June 18, 2002
BOSCH 700 SERIES:
SERVICE INSTRUCTIONS FOR OVEN TESTING AND BASIC TROUBLESHOOTING
PROVIDES THE VFD DISPLAY WITH A LOW ALTERNATE VOLTAGE, REFERRED TO PIN 3
PROVIDES THE VFD DISPLAY WITH POWER SUPPLY (+57V)
PROVIDES THE VFD DISPLAY WITH A LOW ALTERNATE VOLTAGE, REFERRED TO PIN 1
PROVIDES THE BUZZER WITH ITS POWER SUPPLY LINE (THE KEYBOARD DOESN'T USE IT ANYMORE)
PROVIDES ALL THE LOGIC ELECTRONIC COMPONENTS WITH THEIR POWER SUPPLY
GROUND REFERENCE FOR ALL DISPLAY BOARD VOLTAGES
NOTES
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