User Interface Port - Viking VDB200 Service Manual

Service Diagnostics and Procedures
Control Board Diagnosis
Water Temperature Sensor
The dishwasher uses a water temperature sensor
that is mounted in the sump of the dishwasher. It is
an N.T.C (Negative Temperature Coefficient). As
the temp of the water rises, the resistance drops
(and vice-versa).
In the 200 Series dishwasher, it also serves as
a water input sensor as well. During a fill cycle,
an increase or decrease in water temperature is
monitored by the control board. This temperate
change due to incoming water temperature
fluctuations is realized by the board as water
entering the machine. If no change in temperature
is recorded, a FILL error code will be displayed.
If the senor is open, an OPEN fail code will signal
(Refer to page 13 for fail codes).
The control board monitors P8-3 – P8-4. Resistance
should be 47K @ 77˚. If no resistance is found,
Ω
check wiring. If wiring is OK, replacement of the
sensor is necessary.
P-8
© 2010 Viking Preferred Service
(Some measurements require power and others require the unit not to be powered.)
P-8

User Interface Port

The user interface allows the end consumer to make
cycle selections. As the selection is made, the signal
is sent to the control board via a ribbon connection.
Voltage between P9-1 and P9-2 should be 12 VDC.
If no voltage is found, check ribbon connector. If
connector is OK, replacement of the user interface
is necessary (see Control Panel Removal procedure,
page 22).
P-9
User Interface Board
P-9
18