Motorola Gm328 Gm338 Gm398 Detailed 6804112j18 E Manual

Notes For All Schematics and Circuit Boards 2-11
VSF Voltage Super Filtered (5V)
VSTBY 5V Supply for µP when the Radio is switched off
4-LAYER CIRCUIT BOARD DETAIL VIEWING
COPPER STEPS IN PROPER LAYER SEQUENCE
LAYER 1 (L1)
LAYER 2 (L2)
LAYER 3 (L3)
LAYER 4 (L4)
INNER LAYERS SIDE 1
SIDE 2 

2-12 Notes For All Schematics and Circuit Boards
THIS PAGE INTENTIONALLY LEFT BLANK 

3-1
Section 3
SERVICE AIDS
1.0 Recommended Test Tools
Table 3-1 lists the service aids recommended for working on the radio. While all of these items are 
available from Motorola, most are standard workshop equipment items, and any equivalent item 
capable of the same performance may be substituted for the item listed.
Table 3-1   Service Aids
Motorola Part 
NumberDescription Application
RLN4460_Portable Test SetEnables connection to audio/accessory jack. 
Allows switching for radio testing.
RKN4081_...

3-2Test Equipment
2.0 Test Equipment
Table 3-2 lists test equipment required to service the radio and other two-way radios.
Table 3-2   Recommended Test Equipment
Motorola Part 
NumberDescription Characteristics Application
R2600_NTComms System Analyzer 
(non MPT)This monitor will sub-
stitute for items with 
an asterisk*Frequency/deviation 
meter and signal gen-
erator for widerange 
troubleshooting and 
alignment
R2680_NT Comms System Analyzer 
( MPT1327) to be ordered 
with 
RLN1022_ (H/W) RLN1023_...

 GM328/GM338/GM398
Mobile Radios
Controlhead
Service Information
Issue: December, 2003 

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programs contained in the Motorola products described in...

i
Table of Contents
Section 1 overview
1.0 GM328 Model (GCN6112_) ................................................................................. 1-1
2.0 GM338 Model (GCN6114_) ................................................................................. 1-2
3.0 GM398 Model (GCN6115_) ................................................................................. 1-3
Section 2 Theory of Operation
1.0 Introduction...

ii
4.10 Speaker (Remote Mount Configuration only) ............................................... 2-13
4.11 Electrostatic Transient Protection................................................................. 2-13
Section 3 Troubleshooting Charts
1.0 Controlhead GM328 Troubleshooting Flow Chart ............................................... 3-1
1.1 On/Off ............................................................................................................ 3-1
1.2 Microprocessor...

1-1
Section 1
OVERVIEW
1.0 GM328 Model (GCN6112_)
The Controlhead contains the internal speaker, the on/off/volume knob, the microphone connector, 
several buttons to operate the radio and several indicator Light Emitting Diodes (LED) to inform the 
user about the radio status. To control the LED’s and to communicate with the host radio the control 
head uses the Motorola 68HC11E9 microprocessor. 

1-2GM338 Model (GCN6114_)
2.0 GM338 Model (GCN6114_)
The Controlhead contains the internal speaker, the On/Off/Volume knob, the microphone connector, 
several buttons to operate the radio, several indicator Light Emitting Diodes (LED) to inform the user 
about the radio status, and a 14 character Liquid Crystal Display (LCD) for alpha - numerical 
information e.g. channel number or call address name. To control the LED’s and the LCD, and to 
communicate with the host radio the control head uses the...