Low Voltage Board - Viking VDSC367 Service Notebook

Diagnostics
To avoid risk of electrical shock, personal injury, or death, disconnect electrical power source to unit, unless test
procedures require power to be connected. Discharge capacitor through a resistor before attempting to service.
Ensure all ground wires are connected before certifying unit as repaired and/or operational.
J7
P3
P8
P5
48
! WARNING
P4
Pin location
P4-1
P4-2
P4-3
P4-4
P4-5
P4-6
P4-7
P4-8
P4-9
P4-10
P4-11
P4-12
P4-13
P4-14
P4-15
NOTE 1 : Requires an oscilloscope to measure
NOTE 2 :DC voltage- load of meter can affect measurement
P9

Low Voltage Board

Function Voltage range
Dc supply to 4.5 - 5.5 VDC,
thermistors ref to P4-12
Freezer thermistor 0 - 5.5 VDC, ref
input
Refrigerator 0 - 5.5 VDC, ref
thermistor input
Provide zero 26 V p-p to 34V
timing p-p, ref P4-12
DC Fan enable 17.8 vdc - 38
chassis grnd.
Defrost 17.8 vdc - 38
termination
chassis grnd.
Evaporator fan 17.8 vdc - 38
enable vdc, ref to chas-
sis ground
Compressor 17.8 vdc - 38
enable vdc, ref to chas-
sis ground
Defrost termina- 25.8 vdc - 38
tion signal vdc, ref to chas-
Door signal 25.8 vdc - 38
vdc, ref to chas-
PS Reference
-30 vdc 22.8 vdc - 38
vdc, ref to chas-
sis ground
Not used
Not used
Light enable relay 17.8 vdc - 38
vdc, ref to chas-
sis ground
©2012 Viking Preferred Service
Signal
DC
DC
to P4-12
DC
to P4-12
See Note 1
below
DC
vdc, ref to
See Note 2
vdc, ref to below
See Note 2
below
See Note 2
below
See Note 2
below
sis grnd
See Note 2
below
sis grnd
0 vdc DC
See Note 2
below
AC
AC
See Note 2
below