Troubleshooting; Additional Troubleshooting - Chamberlain JDC Manual

Troubleshooting

Additional Troubleshooting

The table below is a guide for best practice system troubleshooting, containing potential causes and corrective actions.
Symptom
Powerhead main
board is off
(no LEDs are lit or
blinking)
(continued)
Possible Causes Diagnosis
Transformer is Transformer has an internal
overheating 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.
AC power absent Verify input AC voltage:
or out of range Measure AC voltage between 'L1'
and 'L2' terminals at EMI filter board
input connector. Verify voltage is
within specifications.
If voltage is outside specifications,
see resolution.
AC input voltage Check whether the transformer
mis-selected connector is plugged in to the
(120V/240V connectors on the EMI filter board
models only) marked '120V' or '240V.'
Verify this matches the input AC
voltage supplied to the operator.
Blown DC input Check fuses:
fuses on main Measure voltage across DC IN fuses.
board
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.
Faulty Powerhead Perform this test only after first
main board 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.
45
Resolution
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 airflow.
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 specification,
consult an electrician.
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.
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.
Turn off 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.