Cause

Possible causes of SC672 include:

• USB communication path failure (USB cable, IPU)
• CTL boot up error and/or operation panel boot up error due to abnormal break in operations of CTL.

Possible causes of operation panel cannot light include:

• USB communication path failure (USB cable, IPU)
• Operation panel cannot communicate with CTL due to CTL boot-up error
  
  
  [A]: Operation Panel
  [B]: IPU
  [C]: Controller
  [D]: USB cable