Chamberlain JDC - Troubleshooting; Additional Troubleshooting

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Troubleshooting
Additional Troubleshooting
The table below is a guide for best practice system troubleshooting, containing potential causes and corrective actions.
Symptom Possible Causes Diagnosis Resolution
Powerhead main
board is o
(no LEDs are lit or
blinking)
(continued)
Transformer is
overheating
Transformer has an internal
thermal protection device which
disconnects AC power if the
transformer overheats.
If the transformer is allowed to cool,
AC power should reconnect and
restore power to the operator.
Transformer should not normally
overheat. If overheating occurs:
Check door for imbalance and/or
resistance
Check ambient temperature and
ensure it is within the operational
ratings of the door operator.
Ensure that air can move freely
around the door operator, and that
dust or other foreign matter is not
preventing airow.
AC power absent
or out of range
Verify input AC voltage:
Measure AC voltage between 'L1'
and 'L2' terminals at EMI lter board
input connector. Verify voltage is
within specications.
If voltage is outside specications,
see resolution.
If voltage is absent, restore power
to the operator. Check for tripped
breakers, blown fuses, faulty AC
wiring, open disconnects, etc.
If voltage is out of specication,
consult an electrician.
AC input voltage
mis-selected
(120V/240V
models only)
Check whether the transformer
connector is plugged in to the
connectors on the EMI lter board
marked '120V' or '240V.'
Verify this matches the input AC
voltage supplied to the operator.
If 240V power is applied when
120V is selected, damage to
other components of the operator
electronics may have occurred.
Ensure voltage selection is
corrected and verify the operator
functions.
Blown DC input
fuses on main
board
Check fuses:
Measure voltage across DC IN fuses.
If voltage is greater than 0.5V, fuses
are blown. See resolution.
Fuses may also be visually
inspected. Fuses should have
their internal metallic fuse element
intact. If there is a break in the fuse
element, fuse is blown.
Replace both DC IN fuses with
automotive style ATO or ATC fuses,
30A 32V. Both DC IN fuses must
be present and intact for proper
operation of the door operator.
Faulty Powerhead
main board
Perform this test only after rst
checking fuses.
Measure DC voltage between 'DC
IN' + and - terminals. Voltage should
be between 30 and 48 volts DC with
motor stopped.
If voltage is present and MAIN PWR
LED is not lit, see resolution.
Turn o AC power and disconnect
batteries (if present) for at least 30
seconds, then reconnect batteries
(if present) and turn on AC power.
If no LEDs are lit after cycling
power, cycle power again as above
but disconnect all cabling from
mainboard except for main power
wiring before restoring batteries/
AC power.
If LEDs still do not light, replace
main board.
If LEDs light after disconnecting
other devices, suspect a short or
overload from a connected device.