I think you're getting into component level repairs.

That part comes up as a Gables "Switch Shutter Wheel".

Gables makes VHF Communication Control Heads and Audio Selector Panels.

Repairs of these components is done in qualified and certified repair shops.

Line maintenance replaces these units when needed, but we do not open the panels up for internal repair.
  
     
 

Would you happen to know which component of the communication system corresponds to part number 700-D41000B, and furthermore, how this component differs from the one identified by part number 700-D41000G?

I have no clue as to the type of system installed on your aircraft.

This would be a add-on from the the original delivery configuration, so I would think you would find information in a Supplemental Maintenance Manual.

What can be done if the numeric pass code has been forgotten?

We recently had a pitot probe that was not pulling enough current in the low power mode to satisfy the current flow relay. The associated overhead warning light and EICAS message were on. The probe "was" getting hot

This problem was noted by the crew right after the first engine was started. The engine speed cards are what turns on the probes in a low heat mode.

When the aircraft was placed in the "air" (or high power) mode, the failure indication was gone. It also was gone when trying the probe heat test switch.

After wasting about an hour chasing relays..... we hung a new probe on the connector and tried low power..... it worked normal.

After digging into the print, it was noted that the test switch puts the probe in a high heat mode.

The main purpose of the flight deck access system is preventing unauthorized entry into the cockpit.

The flight crews can lock/unlock the door with a switch (usually on the overhead panel).

There is a panel on the outside of the door that a numeric...

Please explain what the “flight deck access system controller” is, and describe its function.......