Filter
Top Products
Oven will not
start when the
START pad is
pressed (light
in the cavity
and display
present)
a) Check the “A” switch for proper operation
b) Check the upper door hook to make sure it is actuating the switch
c) Check the wiring from the “A” switch to the controller (DPU) board
d) Check for 25 volts on both contacts of the “A” switch (with the door
closed)
If none of the above solves the problem – replace the controller (DPU) board
PRO-1
Oven will not
start when
MEMORY
(number) pads
are pressed.
Most likely, the oven’s memory (programming) has not been locked. Perform
the PROGRAM LOCK procedure. Refer to programming instructions at the
beginning of service manual.
PRO-1
PRO-2
Oven will not
accept any
programming
instructions
Most likely, the oven is in the PROGRAM LOCK mode. Perform the unlocking
procedure, as per service manual.
PRO-1
PRO-2
Fuse opens
immediately
after the
START pad is
pressed
Most likely, shorted high voltage capacitor is responsible for this symptom.
Also check the interlock switch, high voltage diode (for shorts), protector diode
(where installed), high voltage transformer (for shorts)
PRO-1
PRO-2
Oven
produces
insufficient
heating power
a) Low line voltage
b) Aged magnetron (over 2,000 hours of use)
c) One of the magnetrons has open filament
d) Intermittent or oxidized magnetron connectors
e) One of the high voltage diodes open
f) One of the high voltage transformers open
g) Change in capacitance of the high voltage capacitor
OCS
PRO-1
PRO-2
Loud humming
sound when
oven operates
a) Shorted high voltage diode
b) Shorted high voltage transformer
OCS
PRO-1
PRO-2
Arcing in the
cavity (visible
and/or
audible)
a) Burnt or carbonized food under the bottom ceramic plate or anywhere
else in the cavity
b) Any pointy or sharp metal objects or areas within the cavity
c) Loose rivets of the antenna (OCS models only)
OCS
PRO-1
PRO-2