Troubleshooting for low fan speeds – MAGFAN

Diagnostic codes 744 – 746

Diagnostic codes 744 – 746 occur when a magnetics fan is under performing.

Symptoms

Code Symptoms XPR® models XPR action Code cancels with...
744 The fan tachometer feedback for MAGFAN 1 is less than the minimum acceptable value. All models None
  • Set process
  • Remote on-off
745 The fan tachometer feedback for MAGFAN 2 is less than the minimum acceptable value. All models None
746 The fan tachometer feedback for MAGFAN 3 is less than the minimum acceptable value. XPR460® None

Corrective action

  1. Use the Fan diagnostic codes diagram to identify the location of the MAGFAN 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 J2 and J5 on the fan power distribution Printed Circuit Board (PCB)
    • The wiring to J7 on the control PCB
  3. Examine the 48 VDC power source output.
  4. If the power output is not correct, replace the 48 VDC power source.
  5. Examine the solid-state relay, and make sure that it is operating correctly.
  6. If you do not find any loose connections and the 48 VDC power source and solid-state relay are good, replace the fan.