900LED Dental Light Troubleshooting
Symptom Check Point Possible Cause Solution
Check the sensor/manual (mode selection switch) on the
cuspidor front panel
Sensor/manual switch (mode selection switch) is off Select manual or sensor mode
Check harness between 900 power pcb (CN204) and
sensor/manual mode switch (1:Pink, 2:Bright green)
Disconnection or break of harness if no continuity Repair or replace harness
Check LED module Damage LED module Replace LED module Assy
Check input voltage of LED module (approximately
DC20V)
Disconnection or damage the harness between 900 power
pcb and LED module if there is no power
Repair or replace harness
There is power (current voltage) on the terminal block on
j-box connecting to 900 power pcb > Defective noise
filter section or 900 power pcb.
Replace noise filter or 900 power pcb
There is input power (current voltage) to 900 power pcb
(CN101) > Defective 900 power pcb.
Check the touch less switch Dirty sensor cover Clean the sensor cover (Toush less sensor surface)
Check sensitivity of touchless sensor Improper setting of sensitivity Adjust sensitivity screw on the touch less sensor pcb.
Check harness between sensor pcb (CN1) and sensor
control pcb (CN4) (1:Yellow, 2:Green, 3:Blue)
There is no continuity > Disconnection or damage of the
harness
Repair or replace harness
Check harness between 900 power pcb (CN202, 1:black,
2:White) and sensor control pcb (CN1,1:black, 3:white)
There is no continuity > Disconnection or damage of the
harness
Repair or replace harness
Check harness between sensor control pcb (CN6, 1: light
blue, 2:N/A.) and sensor/manual select switch
There is no continuity > Disconnection or damage of the
harness
Repair or replace harness
Clean the sensor cover (Toush less sensor surface)
Check fixing position of touchless sensor (pcb) >
Replace touchless sensor (pcb)
Can't not improved from above action > Defective sensor
control pcb.
Replace sensor control pcb.
LED2 (Yellow) on the sensor control pcb is not light up
when pass your hand to touchless sensor or continuously
light up before pass your hand to touchless sensor
Light does not turn on
at both manual and
sensor mode
Check input power of 900 power pcb
Light does not turn on
at sensor mode
Check operation of touchless sensor
