Lincoln 1633-000-EA secondary readings are not achieved, replace transformer, Thermocouple

		secondary readings are not achieved,
		replace transformer.
	Temperature display	If proper voltage is present at terminals
		1,2, and 3 on temperature display, but
		but the display is not lighted, recheck
		all connections for tightness. If
		temperature display is still not operating,
		replace the temperature display.
Temperature display	Thermocouple	Connect the thermocouple of a
Inaccurate, erratic		pyrometer to the thermocouple on
Or inoperative		the temperature control board. (be sure
		to maintain proper polarity of
		thermocouple leads—see adjustment
		section for proper procedure.) The
		pyrometer will indicate oven temperature
		display. Measure D.C. millivolts of
		thermocouple at the temperature display.
		See thermocouple chart in section D for
		proper readings. Replace thermocouple
		if proper readings are not achieved. If
		readings are correct on the thermocouple,
		replace temperature display.

Low Profile – 1600 Advantage Series Service Manual – International 11