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SECTION 34 - DIAGNOSTICS AND TROUBLESHOOTING
FORM 160.54-M1
ISSUE DATE: 10/25/2019
JOHNSON CONTROLS
JCI COMPANY CONFIDENTIAL
34
This diagnostic is used to verify Keypad operation and
the microboard’s ability to respond to a pressed key.
See the description of Keypad operation in
of this manual.
PROCEDURE
1. Press each keypad key. As the key is pressed, an
illuminated LED is displayed corresponding to
the key location on the keypad.
2. Press the DIAGNOSTICS key to return to the
MAIN DIAGNOSTICS Screen.
TROUBLESHOOTING
If an LED is not displayed when a key is pressed, the
keypad, keypad ribbon cable or microboard could be
defective. Use the following procedure to locate the
defective component.
1.
Keypad
a. Disconnect the Ribbon Cable from the keypad.
b. Identify row/column coordinate of the key to
c. In the keypad connector, locate the pins of
the row/column coordinate of the key of the
key to be tested.
d. Insert the leads of an Ohmmeter into the pins
identified in step “c” above.
e. Press the key to be tested. If the contact resis-
tance is greater than 100 Ohms, the keypad
is defective.
f. Release the key. If the contact resistance is
greater than 1 Meg Ohm, the keypad is de-
fective.
2.
Ribbon Cable
Using an ohmmeter, perform a continuity test on
all conductors in the ribbon cable. An open circuit
would indicate the Ribbon Cable is defective.
3.
Microboard
There are no checks or measurements to be made
on the microboard. If the keypad and ribbon ca-
ble check OK per the above procedures, the mi-
croboard is most likely the cause of the problem.
KEYPAD TEST
00336VIP
FIGURE 111 -
KEYPAD TEST SCREEN