Motorola Pr400 Basic 6881096c24 A Manual

							6881096C24-AJuly, 2004
Limited Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General 7-3
7.4 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):
 knob remover/chassis opener
 penknife-size screwdriver
 TORX™ T6 screwdriver
scribe
If a unit requires more complete testing or service than is customarily performed at the basic level, 
send this unit to a Motorola Authorized Service Center. See Appendix B for a list of authorized service 
centers.
The following disassembly procedures should be performed only if necessary:
 Chassis Disassembly
 Speaker Disassembly
 PTT Disassembly
7.4.1 Radio Disassembly — Detailed
7.4.1.1  Front Cover from Chassis Disassembly
1.Turn off the radio.
2.Remove the battery (Figure 7-1):
a. Slide the battery latch into the unlock position. Disengage by pushing downward and 
holding the latch towards the front of the radio.
b. With the battery latch disengaged, slide the battery down from the top of the radio about 
1/2 in. Once the battery is free from the battery rails, lift it directly away from the radio.
c. Remove the battery from the radio.
3.Remove the antenna.
Figure 7-1.  Battery Removal
Battery Latch
Lock
Unlock 
						

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7-4Limited Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General
4.Pry off the volume and channel selector knobs from their shafts using the knob remover/chassis 
opener tool (Motorola part # 6686533Z01) (Figure 7-2).  
5.Separate the chassis from the front housing assembly by using the knob remover/chassis opener 
tool. Place the broad side of the opener into the slots located at the base of the radio (Figure 7-3). 
Press the handle of the opener downwards. This pressing action forces the thin inner plastic wall 
toward the base of the radio, releasing the two chassis base tabs.
.  Figure 7-2.  Antenna and Knob Removal
Note:
Both knobs slide on and off. However, the knobs are designed to fit very tightly on the shaft.
Figure 7-3.  Chassis Removal
CAUTION: Marring the front cover O-ring sealing area will prevent the radio from sealing properly. If the 
O-ring is damaged, replace it with a new one.
Note:The speaker wire assembly microphone wire assembly and keypad flex cable connecting
the front housing assembly and the chassis prevent the two units from being completely
separated. 
Radio Chassis
Chassis Opener Knob Remover/
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							6881096C24-AJuly, 2004
Limited Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General 7-5
6.Pull the chassis assembly out of the front cover only until the volume and channel selectors shaft 
just clear the top of the case. (Figure 7-4).
7.Rotate the bottom of the chassis up about 20° to access the keyboard flex 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 (Fig-
ure 7-5).
9.Unplug the speaker wire assembly from the 2-pin connector on the chassis.
10.Unplug the microphone wire assembly from the socket on the chassis.
11.Move the chassis away from the housing and place on a clean work surface.Figure 7-4.  Keyboard Flex Connector
Figure 7-5.  Microphone and Speaker Connections
Radio Chassis
Flex Connector
Speaker Connector
Microphone Connector 
						

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7-6Limited Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General
7.4.1.2  Dust Cover Disassembly
1.Gently pry the top of the dust cover away from the body of the radio. (See Figure 7-6).
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 7-6.  Dust Cover Disassembly
7.4.1.3  Speaker and Microphone Disassembly
1.Remove the screw from the speaker retainer using a T6 Torx screwdriver (Figure 7-7).
2.Lift the retainer off the speaker, sliding end of retainer out of corner slot on the housing.
3.Lift the speaker out from the front housing.
4.Carefully lift microphone assembly out of housing. Note:
The speaker is held in place with a retainer bracket. Be careful not to damage the speaker
when removing the retainer bracket.
Figure 7-7.  Removal Speaker-Microphone Assemblyc. Separate dust
cover from body. b. Rotate dust cover 90
° to a. Pry dust cover from body.
allow key to be removed.
key
Retainer Bracket
Radio Housing
Speaker
Speaker Connector
Microphone Connector
Microphone 
						

							6881096C24-AJuly, 2004
Limited Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General 7-7
7.4.1.4  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 7-8).
5.Lift keypad out of housing. Note:
Use care when removing the keypad retainer to prevent damage to the keyboard flex cable.
CAUTION: Refer to the CMOS CAUTION paragraph (7.3) before removing the main board. Be 
sure to use Electrostatic Discharge protection when handling circuit boards
.
Figure 7-8.  Keypad Removal
!
Keypad Retainer
Flex Cable
Keypad Board
Keypad 
						

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7-8Limited Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General
7.4.1.5  PTT Disassembly
1.If required, the PTT (Figure 7-9) can be disassembly using a small screwdriver, as follows:
a. Insert the tip of a small screwdriver underneath the PTT and unsnap the top tab.
b. Pry the PTT away from the radio housing.
c. Inspect the two hooks. If bent or broken, the PTT must be replaced.
d. Remove the PTT seal. 
7.4.2 Chassis Disassembly
1.Remove the O-ring.
2.Use a Torx™ screwdriver with a T6 bit to remove the four screws (Figure 7-10) holding the main 
board to the chassis.
3.The audio jack shroud can be removed from the main board.
4.Lift the main board from the chassis (Figure 7-10).
5.Remove the battery contact seal.Figure 7-9.  PTT Removal
CAUTION:  Refer to the CMOS CAUTION paragraph (see 3.3) before removing the main board. Be sure 
to use Electrostatic Discharge protection when handling circuit boards.
Screwdriver
PTT Seal
Ta b
Ta b
Hooks
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							6881096C24-AJuly, 2004
Limited Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General 7-9
7.4.3 Radio Re-assembly - Detailed
7.4.3.1  Dust Cover Re-assembly
1.Insert the tail of the dust cap into the bottom hole of the audio jacks housing opening (Figure 7-
11).
2.Press the dust cap until the tail is fully into the hole.
3.Twist the dust cap counter-clockwise until the cap is seated properly onto the recess.
4.Press the cap again to ensure it fully covers the opening for the audio jack.
7.4.3.2  Microphone and Speaker Re-assembly
1.Check that the mic and speaker felts are in position and not damaged. If damaged replace felts.
2.Insert the microphone sub-assembly into the microphone boot.Figure 7-10.  Removal of Main Board from Chassis
Note:
Make sure the dust cap is placed between the keypad retainer mounting post and the side
wall of the radio.
Figure 7-11.  Dust Cap Re-assembly
Main Board
Radio Chassis
Audio Jack Shroud
Flex Cable Connector
O-Ring
12 34 
						

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7-10Limited Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General
3.Insert the Boot and microphone sub-assembly into the microphone recess in the housing and 
route wires as shown in Figure 7-12.
4.Locate the speaker tab and align it with the tab opening in the front housing (Figure 7-13).
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 7-13). Figure 7-12.  Microphone Re-assembly
Note:
Make sure the speaker and microphone wires are routed tightly between the speaker bas-
ket and the housing post.
Figure 7-13.  Speaker Re-assembly
Note:
When fastening the speaker retainer screw, make sure the wires are out of the way to pre-
vent pinching by the retainer.
Microphone
Boot
Microphone Recess
Microphone Position
Speaker Retainer
Speaker
Front Housing Slot
Speaker Tab
Tab Opening 
						

							6881096C24-AJuly, 2004
Limited Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General 7-11
7.Install the retainer screw using a T6 Torx screwdriver. Torque to 2.3 - 2.5 lb/in.
7.4.3.3  Keypad and LCD/Keyboard Re-assembly
1.Attach the flex cable connector from the LCD module to the keyboard, if not already attached 
(Figure 7-15).
2.Remove protective mylar from window and from keypad, if present.
3.Install the new keypad into the housing. Use the two housing posts for keypad alignment (Figure 
7-14).
4.Remove mylar from LCD if present.
5.Install the LCD/Keypad sub-assembly into the housing (Figure 7-15). Figure 7-14.  Keypad Re-assembly
Figure 7-15.  LCD/Keypad Board Re-assembly
Limited Keypad
Housing Posts
Flex Cable from LCD Module
Flex Cable to Main PC Board 
						

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7-12Limited Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General
6.Attach the flex cable connector into the connector on the keypad board, if not already connected.
7.Bend the flex cable connector as shown (Figure 7-15).
7.4.3.4  Keyboard Retainer Re-assembly
1.Insert the flex cable connector through the slot at the bottom of the keyboard retainer (Figure 7-
16).
2.Insert the two top tabs of the keyboard retainer into the two tab retainers located on each side of 
the speaker in the front housing (Figure 7-16).
3.Press the four keypad retainer locking tabs into the housing.
4.Push the speaker and microphone wires into the top left hand corner of the housing.
7.4.3.5  Chassis Assembly/Re-assembly
1.Replace the battery contact seal (if necessary) surrounding the battery contact (Figure 7-17).
2.Remove the old Interface Pad from the chassis by scraping off the pad and adhesive with a 
straight razor. Use rubbing alcohol and a cloth to completely remove the adhesive from the chas-
sis surface. With the chassis clean and dry, add a new Interface Pad to the chassis.
3.Place the main circuit board straight down on top of the chassis with the frequency and volume 
switches facing down (Figure 7-17).
4.Use the T6 Torx screwdriver to fasten the screws holding the main board to the chassis. Tighten 
to 3.7 - 3.9 in/lb.
CAUTION: Make sure the microphone and speaker wires are not trapped under the LCD mod-
ule.
Figure 7-16.  Keyboard Retainer Re-assembly
Note:
Be sure the battery contact seal protrudes through the chassis and is not pinched under the
chassis.
!