Viking Designer DEDO530T, Service Manual

Page: 58 / 73

Diagnostics
© 2008 Viking Preferred Service
58
Main Control Board
The operation of the oven is achieved by input from the control panel to the Main Control board. The main
control board wills active the required relay on the relay board. The main control board senses the inputs from
the RTD’s, Hall sensors, door interlock switch, door lock position switch SW1 and SW2 and the Meat probe.
The main control board is connected to the display board and the keyboard by the use of wire connections In a
Molex disconnect plug. The Keyboard connection is a 6-wire connector while the display cable is a 7-wire
connection.
KEYBOARD
If you receive the KEYBOARD ERROR code or have an inoperative - erratic keyboard, first try to run the
Individual Keyboard Test on Page 17 of this manual. If you are unable to run the test, check for the control
voltages from the output of the Main Control Board.
FIG A shows the location of the Keyboard connection on
the Main Control Board. FIG B shows the Molex connection P3 close-up.
VOLTAGES
Pin (1) and Pin (2) +5 VDC
Pin (6) and Pin (5) +10 VDC
If the voltages are correct, unplug the Molex plug
from both the main control board and the Keyboard
and Ohm out the 6 wires in the cable. If the cables checks ok
then replace the Keyboard assembly.
If the voltages are incorrect replace the Main Control Board.
Pin identifier
Pin 1 = Output – VCC, +5 Vdc supplied to the keyboard logic
Pin 2 = Output – Ground reference to the keyboard
Pin 3 = I ² C – Reset line
Pin 4 = I ² C – SCL (serial clock)
Pin 5 = I ² C – SDA (serial data)
Pin 6 = Output – V-Display (+10 Vdc supplied to the Keyboard backlight)
6 5 4 3 2 1