Table 7-2.--Microphone Control Station Trouble Chart

rack. If power is not available, check the position of the

localized by using the test meters and meter test switches

included in the control and power racks. Also, the use

supply switch on the main IC switchboard.

of duplicate oscillator, preamplifier, and power

If power is available, check all fuses and switches

amplifier assemblies permits the testing or repair of one

associated with the system. If a fuse failure is indicated,

assembly while the other assembly remains in active

replace the fuse. If the new fuse burns out immediately,

service, thereby avoiding the necessity for shutting

do not replace it a second time until the cause has been

down the system.

corrected. A check of the switches on both the control

If the entire announcing system is inoperative, the

rack and the microphone control stations may show that

trouble is probably in the ship's power supply or wiring

one or more are not in the proper position.

from the ship's power supply. Check the power available

Tables 7-2, 7-3, and 7-4 are trouble charts for the

indicator on the control rack. This indicator, unless it is

defective, will be lighted when power is available to the

system. These tables show some of the more common

Table 7-2.--Microphone Control Station Trouble Chart

7-22