Page 140
Troubleshooting Guides
Integrated (
Integrated (
700-
700-
2) Series
2) Series
8-34
#
3756780
- Revision D - July, 2005
BASE UNIT MEMBRANE SWITCH / RIBBON CABLE TEST
If the integrity of a Base Unit control panel assembly is suspect, continuity tests should be performed at the mem-
brane 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.
700BR-2 Membrane Switch/Ribbon Cable Test Procedure
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 across pins 3 & 4.
3. Press Door Ajar Alarm ON/OFF key, there should be continuity across pins 2 & 4.
4. Press Upper Drawer WARMER key, there should be continuity across pins 4 & 5.
5. Press Upper Drawer COLDER key, there should be continuity across pins 1 & 3.
6. Press Lower Drawer WARMER key, there should be continuity across pins 1 & 2.
7. Press Lower Drawer COLDER key, there should be continuity across pins 1 & 5.
NOTE:
If any of the tests show failure, replace entire control panel assembly.
700BF/I-2 Membrane Switch/Ribbon Cable Test Procedure
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 across pins 3 & 4.
3. Press Door Ajar Alarm ON/OFF key, there should be continuity across pins 2 & 4.
4. Press ICE ON/OFF key, there should be continuity across pins 4 & 5.
5. Press WARMER key, there should be continuity across pins 1 & 2.
6. Press COLDER key, there should be continuity across pins 1 & 5.
NOTE:
If any of the tests show failure, replace entire control panel assembly.
DRAWER
UPPER
COLDER
WARMER
ON/OFF
UNIT
DRAWER
LOWER
ON/OFF
COLDER
WARMER
Terminal Housing
NOTE
: See “How To Identify Pin 1”, above.
Ribbon Cable
Membrane Switch in
Control Panel Assembly
Figure 9-2. Base Unit Control Panel Assembly with Cut-Away View to Show Ribbon Cable
(700BR-2 Shown)