Troubleshooting for low fan speeds – CTRLFAN 1 / CAB FAN 1

Diagnostic codes 747 and 750

XPR170® and XPR300®: Diagnostic code 750 occurs when the CTRLFAN 1 fan is not operating to specifications.

XPR460®: Diagnostic code 747 occurs when the CAB FAN 1 fan is not operating to specifications.

Symptoms

Code Symptoms XPR® models XPR action Code cancels with...
747 The fan speed for CAB FAN 1 is less than the minimum acceptable Revolutions Per Minute (RPM) value. XPR460 None
  • Set process
  • Remote on-off
750 The fan speed for CTRLFAN 1 is less than the minimum acceptable RPM value. XPR170, XPR300

Corrective action

  1. Use the Fan diagnostic codes diagram to identify the location of CTRLFAN 1 (XPR170, XPR300) or CAB FAN 1 (XPR460) in the plasma power supply.
  2. Make sure that the following fan connections are good, and tighten loose connections if found:
    • The fan connector
    • The wiring to J7 on the fan power distribution Printed Circuit Board (PCB)
    • The wiring to J7 on the control PCB
  3. Tighten loose connections if found.
  4. Examine the 48 VDC power source output.
  5. If the power output is not correct, replace the 48 VDC power source.
  6. If you do not find any loose connections and the 48 VDC power source is good, replace the fan.