Page 139
Troubleshooting Guides
Integrated (
Integrated (
700-
700-
2) Series
2) Series
8-33
#
3756780
- Revision D - July, 2005
TALL UNIT MEMBRANE SWITCH / RIBBON CABLE TEST
If the integrity of a Tall Unit control panel assembly is suspect, continuity tests should be performed at the membrane
switch ribbon cable terminal housing. Begin by disconnecting the ribbon cable from the control board. Disengage
the control board from the control panel. Remove the control panel assembly from the unit and place it on a solid
surface.
How To Identify Pin 1 on Terminal Housing
The ribbon cable wires are exposed at the back of the terminal housing, but since there are two vendors of the
membrane switch, determining the location of pin 1 is not always easy. To identify the pins, follow these guidelines:
1.
If the terminal housing is BLUE, then pin 1 is closest to the arrow on the housing.
2. If the terminal housing is BLACK, check for continuity between the first two pins at each end of the housing
while pushing UNIT ON/OFF key. If there is continuity, then pin 1 is at that end.
Test Procedure
NOTE:
Unless mentioned, the continuity tests described below are the same for all tall models. If any of the tests
show failure, replace entire control panel assembly.
1. Press no keys on the membrane switch. Check for continuity between all pin combinations. With no keys
pressed, there should be no continuity between any of the pins.
2. Press UNIT ON/OFF key, there should be continuity between pins 1 & 2.
3. Press Door Ajar Alarm ON/OFF key, there should be continuity between pins 2 & 5.
4. Press ICE ON/OFF key, there should be continuity across pins 2 & 3.
5. Press Refrigerator (700TR-2 Upper) WARMER key, there should be continuity across pins 1 & 6.
6. Press Refrigerator (700TR-2 Upper) COLDER key, there should be continuity across pins 5 & 6.
7. With the Freezer (700TR-2 Lower) WARMER key depressed, there should be continuity across pins 3 & 4.
8. With the Freezer (700TR-2 Lower) COLDER key depressed, there should be continuity across pins 4 & 5.
Figure 9-1. Tall Unit Control Panel Assembly with Cut-Away View to Show Ribbon Cable
(700TCI-2 Shown)
UNIT
UNIT
ICE
ICE
WARMER
WARMER
COLDER
COLDER
REFRIGERATOR
REFRIGERATOR
ON/OFF
ON/OFF
ON/OFF
ON/OFF
ON/OFF
ON/OFF
WARMER
WARMER
COLDER
COLDER
FREEZER
FREEZER
Terminal Housing
NOTE
: See “How To Identify Pin 1”, above.
Ribbon Cable
Membrane Switch in
Control Panel Assembly