Motorola Pr400 Basic 6881096c24 A Manual

							6881096C24-AJuly, 2004
Non-Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General 8-5
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 8-4).
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 8-4).
7.Unplug the speaker wire assembly from the 2-pin connector on the chassis.
8.Unplug the microphone wire assembly from the socket on the chassis.
9.Move the chassis away from the housing and place on a clean work surface.
8.4.1.2  Dust Cover Disassembly
1.Gently pry the top of the dust cover away from the body of the radio. (See Figure 8-5).
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 8-5.  Dust Cover Disassembly Figure 8-4.  Microphone and Speaker Connections
Speaker Connector
Microphone
ConnectorShroud
key
c. Separate dust
cover from body. b. Rotate dust cover 90° to a. Pry dust cover from body.
allow key to be removed. 
						

							July, 20046881096C24-A
8-6Non-Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General
8.4.1.3  Speaker and Microphone Disassembly
1.Remove the screw from the speaker retainer using a T6 Torx screwdriver (Figure 8-6).
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.
8.4.1.4  PTT Disassembly
1.If required, the PTT (Figure 8-7) 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.  Note:
The speaker is held in place with a retainer bracket. Be careful not to damage the speaker
when removing the retainer bracket.
Figure 8-6.  Removal Speaker-Microphone Assembly
Retainer Bracket
Radio Housing
Speaker
Wire Connector
Microphone Assembly 
						

							6881096C24-AJuly, 2004
Non-Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General 8-7
8.4.2 Chassis Disassembly
1.Remove the O-ring.
2.Use a Torx™ screwdriver with a T6 bit to remove the four screws (Figure 8-8) 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.
5.Remove the battery contact seal.Figure 8-7.  PTT Removal
CAUTION:  Refer to the CMOS CAUTION paragraph (8.3) before removing the main board. Be sure to 
use Electrostatic Discharge protection when handling circuit boards.
Figure 8-8.  Removal of Main Board from Chassis
Flat BladeScrewdriver
PTT Seal
Ta b
Ta b
Hooks
!
Main Board
Radio Chassis
Audio Jack Shroud
O-Ring 
						

							July, 20046881096C24-A
8-8Non-Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General
8.4.3 Radio Re-assembly - Detailed
8.4.3.1  Dust Cover Re-assembly
1.Insert the tail of the dust cap into the bottom hole of the audio jacks housing opening (Figure 8-9).
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.
8.4.3.2  Microphone and Speaker Re-assembly
1.Check that the speaker felt is in position and is not damaged. If damaged replace felt.
2.Insert the microphone sub-assembly into the microphone boot.
3.Insert the Boot and microphone sub-assembly into the microphone recess in the housing and 
route the wires as shown in Figure 8-10.
4.Locate the speaker tab and align it with the tab opening in the front housing (Figure 8-11).
5.Insert the speaker tab into the speaker recess in the housing. Ensure the speaker is seated flush 
in the housing.Figure 8-9.  Dust Cap Re-assembly
Figure 8-10.  Microphone Re-assembly
12 34
Microphone
Boot
Microphone Recess
Microphone Position 
						

							6881096C24-AAugust, 2004
Non-Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General 8-9
6.Insert one end of the speaker retainer into the slot in the front housing (See Figure 8-11).
7.Install the retainer screw using a T6 Torx screwdriver. Torque to 2.3 - 2.5 lb/in.
8.4.3.3  Chassis Assembly/Re-assembly
1.Replace the battery contact seal (if necessary) surrounding the battery contact (Figure 8-12).
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 8-15.
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.
5.Replacing the O-ring.
a. If you have the older chassis (2786389Z01) use the older O-ring (3286431Z02). Position 
the O-ring in the top groove by the volume/frequency switches. Stretch the O-ring to 
place it into the retaining groove at the bottom end of the chassis. Note:
Make sure the speaker and microphone wires are routed tightly between the speaker bas-
ket and the housing post
Figure 8-11.  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.
Note:
Be sure the battery contact seal protrudes through the chassis and is not pinched under the
chassis.
Speaker Retainer
Speaker
Front Housing Slot
Speaker Tab
Tab Opening 
						

							August, 20046881096C24-A
8-10Non-Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General
b. If you have the newer chassis (2786389Z02) use the newer O-ring (3286431Z05). Posi-
tion the O-ring with the plug on the right side (speaker connector side). Push the plug all 
the way into the chassis slot until it is touching the chassis flange. Repeat for the left 
side. Stretch the O-ring to place it into the retaining groove at the top and bottom end of 
the chassis.
6.Check that the O-ring is not twisted and is being held by the top and bottom chassis groves.
7.Replace the audio jack shroud.
8.4.3.4  Chassis and Front Cover Re-assembly
1.Dress and connect the speaker wires.
a. Connect the speaker wire assembly into the 10-pin connector on the main board and 
bend the wires at the board connector so the wires are positioned toward the top of the 
radio (Figure 8-13). 
b. Connect the microphone wire assembly into the two hole socket on the main board and 
bend the wires at the board connector so the wires are positioned toward the top of the 
radio (Figure 8-13).
c.Slide the audio jack shroud onto accessory connector (Figure 8-12).
2.Slide the volume potentiometer and frequency switch shafts into their respective holes in the front 
cover. Look through the accessory connector opening to make certain that the wires are not 
pinched.Figure 8-12.  Installation of Main Board onto Chassis
Note:
Care should be taken when dressing the speaker and microphone wires to avoid pinching
them between the speaker magnet and shield, or between the accessory connector and
housing.
Note:
Ensure that the plug orientation is correct with the exposed pins in the wire casing facing
upward and fully plugged in.
Main Board
Radio Chassis
Battery Contact Seal
Interface Pad
Frequency & 
Volume SwitchesAudio Jack Shroud
(Replace after Plugging
in Speaker and Mic)
O-ring 
						

							6881096C24-AAugust, 2004
Non-Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General 8-11
3.Push the topside of the board chassis upward until it touches the housing end. Before snapping 
the board into the housing, perform the following checks.:
a. Open the dust cap and ensure the wires are not pinched between the shroud and housing.
b. Ensure the O-ring is seated in the groove.
c. Ensure that the bottom side of the dust cap is fully pressed into the housing before the 
snapping the board into place.
4.Snap chassis assembly completely into the top of the front cover (Figure 8-14) until it settles in 
place.
5.Make sure the O-ring is properly seated. If the O-ring seal is pinched, separate the chassis from 
the housing using the knob removal/chassis opener and dress O-ring properly.
6.Snap the bottom of the chassis into the front cover.
7.Check that O-ring is visible at the corners.
8.Re-assemble the knobs, antenna, and battery.Figure 8-13.  Microphone and Speaker Wires Re-assembly
Figure 8-14.  Fastening the Chassis
Speaker Connector
Microphone
Connector
Shroud
Radio Chassis 
						

							August, 20046881096C24-A
8-12Non-Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General
8.4.3.5  PTT Re-assembly
1.Place the PTT seal over the ridge around the top hole. Press down to seat the seal around the 
ridge.
2.Place the bottom tab in the slot inside the front housing PTT opening. Slightly slide down the PTT 
and bow it by placing one finger under the middle of the PTT, so that the top tab can be aligned 
and inserted into the top slot (Figure 8-15a).
3.Press the PTT assembly against the front cover opening (Figure 8-15b).
Figure 8-15.  PTT Re-assembly a. Place bottom tab into bottom slot.
Place top tab into top slot.b. Push down on PTT toward bottom
of radio so hooks do not get crushed. 
						

							6881096C24-AAugust, 2004
Non-Keypad Model Disassembly and Re-assembly: Mechanical View and Parts List 8-13
8.5 Mechanical View and Parts List
8.5.1 PR400 Non-Keypad Exploded View and Parts List
Figure 8-16.  PR400 Non-Keypad Radio Exploded View
1
22 23
26
2
3
4
5
6
7 8
9
10 11
12 13
1415
16
17
18
19
20
24
25
21
27 
						

							8-14Mechanical View and Parts List
August, 2004 6881096C24-A
ItemMotorola
Part
Number Description
1See Section 6Antenna
2 3680530Z02 Knob, Frequency
31386440Z02Escutcheon, Top; 16 Ch.
4 5886627Z01 Antenna Adaptor / Seal
51586391Z01Housing, Plain
6 3586621Z01 Felt, Speaker
73886489Z01PTT, Rubber
8 4586439Z01 PTT, Plastic
90186638Z01Speaker Assembly
10 4286620Z01 Retainer, Speaker
113586621Z02Felt, Microphone
12 0780608V01 Boot, Microphone
130186639Z01Microphone Plug Assembly
14 3286431Z05 Seal, Main O-ring
157586436Z02Pad, PA Interface
16 2786389Z02 Chassis
173286435Z01Seal, Battery Contact Block
18 0304726J05 Screws, Chassis; 4 Used
191586437Z01Shroud, Audio Jack
20 5586445Z02 Latch Assembly
214105944K01Spring, Latch; 2 Used
22 3886441Z01 Cap, Dust
233286432Z01Seal, Control Shaft
24 3386443Z01 Label, Escutcheon Seal
256186446Z02Lightpipe
26 3680529Z01 Knob, Volume
270386434Z01Screw, Speaker Retainer
NON-REFERENCED ITEMS
3386625Z01Nameplate, Motorola