Installation Manual

GMA 240 Installation Manual 190-00917-01
Page 2-2 Rev. D
2.3.1 Internal Configuration Jumpers
The following internal configuration adjustments may be made by removing or replacing jumpers on the
PCB. The jumper positions are designed to accept a 0Ω resistor of 0603 size. Refer to Appendix C
for
component location.
This service should only be performed by a qualified technician. Garmin is not responsible for damage
caused during adjustment of these internal configuration jumper settings. Refer to the GMA 240
Maintenance Manual for disassembly/reassembly instructions.
Figure 2-1 ESD Caution Logo
NOTE
The GMA 240 contains static sensitive components. Observe proper anti-static
procedures when performing any solder procedures on the unit.
Table 2-1 Configuration Jumpers
Component Name Default Description
R0303
Alert Mutes
Music
Populated
If this jumper is removed, music will not be interrupted by
alert audio. Default operation is recommended.
R0304
COM1
Internal
Sidetone
Empty
If a jumper is supplied in these positions, internal sidetone
will be heard during PTT to simulate received sidetone
from a radio that does not provide one during
transmission. This should only be used if a radio does not
perform this function already.
R0305
COM2
Internal
Sidetone
Empty
R0308
TEL
Internal
Sidetone
Populated
If this jumper is removed, intercom audio and intercom
sidetone will not be heard when the TEL button is
selected. Many phones supply sidetone when a call is in
session. This causes a noticeable change in intercom
sound quality but it is usually not disruptive. Default
operation is recommended unless the effect of sidetone
from the telephone is disruptive to intercom operation.
R0315
TEL jack
detect
bypass
Empty
If a jumper is supplied in this position, when TEL is
selected the audio panel will assume a telephone is in use
in the front jack regardless of phone detection. This
should be used only if the audio panel is not capable of
properly detecting the telephone that will be used in the
installation.