NuTone IM-440 Series Diagnostic Tests, Resetting the Microprocessor, KEY Display

OPERATIONAL CHECKOUT (Continued)

DIAGNOSTIC TESTS

The following diagnostic tests have been incorporated into the NuTone IM-4406 master station to assist in system troubleshooting.

•Master station keyboard test

•Remote station control voltage test

•Display test

The following applies to all diagnostic tests:

1.To access any of the diagnostic tests, the system must be in the PROGRAM OFF mode.

2.Pressing the MEMORY SET key will end the current diagnostic test.

3.The current diagnostic test will end after one minute of inactivity.

PLEASE NOTE: An incorrect voltage caused by miswiring, shorted wiring or a defective remote station may cause the radio and/or CD Player to turn off/on, thus preventing the unit from entering the diagnostic mode. Should this occur, the master station’s control timer will stop the on/off cycling after 30 seconds.

Remote Station Keyboard Test – Verifies that all keys on the master station are functioning properly. To activate: Press and hold the following key in this order:

1.	▲ key	3.	Memory 1 key
2.	▼ key	4.	Release all keys

In this mode, the hours in the display represents the current diagnostic test and the minutes indicate the current key being pressed. The following will be displayed as the key is pressed.

KEY	DISPLAY	KEY		DISPLAY
No key	1:00	Memory 2		1:14
Scan	1:01	Memory 3		1:15
▲	1:02	Memory 4		1:16
▼	1:03	Memory 5		1:17
Program Off	1:04	Memory 6		1:18
AM	1:05	Play/Pause		1:19
FM	1:06	RDM/RPT		1:20
Tape	1:07	Track	▲	1:21
Aux	1:08	Track	▲	1:22
Timer	1:09	Display		1:23
Inside/Patio	1:10	Stop		1:24
Door Talk	1:11	Time Set		1:25
End Call	1:12	Memory Set		1:26
Memory 1	1:13

Remote Station Control Voltage Test – Displays the voltage at the master’s microprocessor control line. To activate, press and hold the following keys:

1.	▲ key	3.	Memory 2 key
2.	▼ key	4.	Release all keys
Example:
	Display	Voltage at Microprocessor
	2:3.0	3.0 volts
	2:1.9	1.9 volts
	2:0.1	.1 volts

In this mode, the hours represent the diagnostic test, and the minutes indicate the voltage at the master station’s microprocessor.

	Voltage Window
Mode	Maximum	Minimum
End Call	.4 volts	0 volts
Inside/Patio	2.4 volts	1.6 volts
Door Talk	3.6 volts	2.8 volts
Quiescent	5.0 volts	4.3 volts

The control voltage windows for the three intercom modes and quiescent mode are listed above. For proper intercom operation, the control voltage produced when an intercom key is pressed at a remote station should fall between the voltage indicated.

NOTE: Pressing the END CALL, DOOR TALK, or INSIDE/PATIO keys at the master station will not change the voltage on the control line. If a remote station does not produce a voltage within the above window for a specific intercom function, check the following:

•Make sure all connections from the master station are properly installed at the terminal board.

•Check IW-6 connections at the master station terminal board and at each remote station.

•Confirm that the suspect remote station functions properly by replacing it with a known good remote station.

Display Test – Displays all segments in the LCD display. To activate, press and hold the following in this order:

1.	▲ key	3.	Memory 3 key
2.	▼ key	4.	Release all keys

RESETTING THE MICROPROCESSOR

NOTE: Resetting the microprocessor will cause the radio memory channels and clock time to be lost.

Should the system not operate properly, the internal microprocessor may require resetting. To reset the microprocessor, use the point of a pen to press the reset button through the access hole behind the right lower door. See “System Operating Control” section.

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