Duke DSO 500, Service Manual

Page: 69 / 80

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unit(s). If current is above normal operat-
ing specs, replace magnetron unit(s).
If magnetrons are operating check stirrer
motor wire connections and confirm that
supply voltage is present at stirrer motor
terminals. If supply voltage is present
replace stirrer motor.
Note: Stirrer motor stops when door is
open.
If magnetrons are not working refer to
“Oven will not operate (Magnetrons)”
and use the “Door interlock circuit
mechanical relays” instructions.
Check for supply voltage at the L1 and
L2 terminals on the inverter. If supply
voltage is not present trace wiring back
to source to insure proper connection. If
supply voltage is present check output
voltage to blower motor at terminals T1,
T2 and T3. If output voltage is not pres-
ent check for incoming control signals
at terminals 3, 5, 8, 9 and 10. If control
signals are not present trace and check
wiring back to the electronic control
board.
Check for control output signals at ter-
minals 1 thru 10 of the upper and lower
blower units. If no signals are present
replace the electronic control board.
If output voltage is present at inverter
terminals T1, T2 and T3 insure that
same voltage is present at motor electri-
cal connections. If output voltage is not
present, replace the wiring harness.
If inverter output voltage is present at
the motor electrical connections and
motor does not operate, replace the
blower motor.
SYMPTOM POSSIBLE CAUSE REMEDY
Current sensors detect
overload state
Stirrer Motor
Mechanical Relay Prima-
ryK6
Inverter Drive
Electronic Control Board
Wiring harness
Blower Motor
Magnetrons operate
intermittently
Stirrer motor will not
operate
Convection blower motors
will not operate
TROUBLESHOOTING