Motorola Pr400 Basic 6881096c24 A Manual

Chapter 6 Full Keypad Model Disassembly and
Re-assembly
6.1 Introduction
This section provides details about the following:
• Preventive maintenance (inspection and cleaning)
 Safe handling of CMOS and LDMOS devices
 Disassembly and re-assembly of the radio
 Repair procedures and techniques
6.2 Preventive Maintenance
The radios do not require a scheduled preventive maintenance program; however, periodic visual 
inspection and cleaning is recommended.
6.2.1 Inspection
Check that the external surfaces...

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6-2Full Keypad Model Disassembly and Re-assembly: Safe Handling of CMOS and LDMOS Devices
Cleaning Internal Circuit Boards and Components
Isopropyl alcohol (70%) may be applied with a stiff, non-metallic, short-bristled brush to dislodge 
embedded or caked materials located in hard-to-reach areas. The brush stroke should direct the 
dislodged material out and away from the inside of the radio. Make sure that controls or tunable 
components are not soaked with alcohol. Do not use...

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6.4 Disassembling and Re-assembling the Radio — General
Since these radios may be disassembled and re-assembled with the use of only four (board to casting) 
screws, it is important to pay particular attention to the snaps and tabs, and how parts align with each other.
The following tools are required for disassembling the radio (see Chapter 4 for a list of service aids):
...

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6-4Full Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General
3.Remove the antenna.
4.Pry off the volume and channel selector knobs from their shafts using the knob removal/chassis 
opener tool (Motorola part # 6686533Z01). (Figure 6-2).
5.Separate the chassis from the front housing assembly by using the knob remover/chassis opener 
too. Place the broad side of the opener into the slots located at the base of the radio (Figure 6-3). 
Press...

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7.Rotate the bottom of the chassis up about 20 ° to disconnect the keyboard flex cable connector. 
Push down 2 end tabs to release flex connector at the bottom of the chassis.
8. Rotate the chassis counterclockwise out of the housing and position next to the housing. Take 
care not to damage the speaker  and microphone wires that are still connected to the chassis 
( Figure...

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6-6Full Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General
6.4.1.2  Dust Cover Disassembly
1.Gently pry the top of the dust cover away from the body of the radio. (See Figure 6-6).
2.Rotate the dust cover 90° in a counterclockwise direction to allow the key to be removed.
3.Separate the dust cover away from the body of the radio. The dust cover key is fragile; apply only 
light pressure to the key while removing the dust cover.
Figure 6-6....

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6.4.1.4  Keyboard Removal
1.Carefully pry the four keypad retainer locking tabs free from the housing using a scribe.
2. Lift the keypad retainer up from the bottom and slide the top tabs out.
3. Slide keypad retainer out of housing carefully to prevent damage to flex cable.
4. Lift LCD keypad board out of housing ( Figure 6-8).
5. Lift keypad out of housing.
6.4.1.5  PTT...

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6-8Full Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General
6.4.1.6  Chassis Disassembly
1.Remove the O-ring.
2.Use a Torx™ screwdriver with a T6 bit to remove the four screws (Figure 6-10) holding the main 
board to the chassis.
.
3.The audio jack shroud can be removed from the main board.Figure 6-9.  PTT Removal
CAUTION:  Refer to the CMOS CAUTION paragraph (see 3.3) before removing the main board. Be sure 
to use Electrostatic Discharge...

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4.Lift the main board from the chassis ( Figure 6-10).
5. Remove the battery contact seal.
6.4.2 Radio Re-assembly - Detailed
6.4.2.1  Dust Cover Re-assembly
1.Insert the tail of the dust cap into the bottom hole of the audio jacks housing opening
(Figure 6-11 ).
2. Press the dust cap until the  tail is fully into the hole.
3. Twist the dust cap counter-clockwise until the...

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6-10Full Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General
4.Locate the speaker tab and align it with the tab opening in the front housing (Figure 6-13).
5.Insert the speaker tab into the speaker recess in the housing. Ensure the speaker is seated flush 
in the housing.
6.Insert one end of the speaker retainer into the slot in the front housing (See Figure 6-13).
 
7.Install the retainer screw using a T6 Torx screwdriver. Torque to 2.3 -...