The control room module is so to speak the nerve centre of the console, so in order to
  ensure minimum down time, the following procedures are adopted.
 
  All IC's are plug-able.

  Various regions of the PCB have isolation resistors that burn out, and become open 
  circuit to localize the fault. These are mounted off the PCB to prevent track damage.

  The headphone amplifier has push-pull power transistors fitted giving sufficient margin.

  All electrolytic capacitors are long life types (105c) this applies to all modules.

  Source select switches total 6, are mounted on a removable module. Easy to replace.