Lincoln Impinger X2 Ovens with Push Button Controls 3270-2 - Manual (Page 13)

Impinger X2 – Digital Service Manual – Dom & Int’l 13
there is voltage, connect a manometer to the pressure
tap fitting on the gas valve. If there is voltage to the
pilot valve, but there is no gas pressure, replace gas
valve.
Pilot tube Check for gas pressure at pilot tube. Disconnect pilot
tube at burner and connect manometer. If there is no
gas pressure, check for blockage in pilot tube. Repair
or replace tube as needed.
Pilot orifice If there is gas pressure at the pilot tube, check the pilot
orifice for blockage or obstructions. Replace pilot orifice
as needed.
Flame will not stay on Flame sensor To check flame sensor operation, connect a digital
multimeter (capable of measuring D.C. Microamps)
between the flame sensor wire and the flame sensor
connection on the ignition control (terminal #3). Flame
sensor current is to be 0.7 microamp, minimum. If
these readings are not achieved, replace igniter/sensor
assembly. Also check for any type of damage to flame
sensor wire and connections.
NOTE: The D.C. microamp test must be conducted
with the oven in low flame operation.
Power supply Set the temperature to the lowest temperature setting.
If there is sufficient microamp current, but the flame will
not stay lit, check for proper polarity of the power
supply.
Burner control If there is sufficient microamp current, and there is
proper polarity of the power supply, but the burner will
not stay lit, check the reset button for the burner
control. If the above test is okay, replace the burner
control.
NOTE: Flame should be
on at this time
Low flame is on, but no main
flame Transformer, control Check for supply voltage to primary of control
transformer. If no voltage is present, trace wiring back
to the main fan switch. If voltage is present, check for
24VAC at transformer secondary.
If there is primary voltage but no secondary voltage,
replace burner/control transformer.
Oven control Check for 24VAC supply to oven control. If no voltage
is present, trace wiring back to control transformer. If
24VAC is present, check for a read-out on the display.
If there is 24VAC supplied, but there is no read-out on
the display, replace oven control. If there is a read-out
on the control, set the control to maximum temperature
(see Installation operations manual for temperature
adjustment). With the control set at maximum
temperature, check for supply voltage at the
temperature regulation valve. If there is voltage at the
temperature regulation valve, proceed to “Temperature
regulation valve” for next check. If there is no voltage at
the temperature regulation valve, trace wiring back to
the oven control. If there is no voltage output at the
oven control, check the read-out on the oven control. If
the control reads “PROBE FAIL”, this indicates that the
thermocouple has failed or become disconnected from
the oven control.
Thermocouple probe Check to be sure that the thermocouple is securely
connected to the oven control. If the thermocouple is
connected to the oven control, and the control indicates
“PROBE FAIL”, disconnect the thermocouple from the
oven control and measure the resistance of the