Motorola Pr400 Basic 6881096c24 A Manual

							6881096C24-A     July, 2004
Full Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General 6-11
6.4.2.3  Keypad and LCD/Keyboard Re-assembly
1.Attach the flex cable from the LCD module to the keyboard, if not already attached ( Figure 6-15).
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 6-14 ).
4. Remove mylar from LCD if present.
5. Install the LCD/Keypad sub-assembly into the housing ( Figure 6-15).
Figure 6-14.  Keypad Re-assembly
CAUTION: 
 Make sure the microphone and speaker wires are not trapped under the LCD module.
Figure 6-15.  LCD/Keypad Board Re-assembly
Full Keypad
Housing Posts
!
Flex Cable from LCD Module
Flex Cable to Main PC Board 
						

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6-12Full Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General
6.Attach the flex cable into the connector on the keypad board, if not already connected.
7.Bend the flex cable as shown (Figure 6-15).
6.4.2.4  Keyboard Retainer Re-assembly
1.Insert the flex cable through the slot at the bottom of the keyboard retainer (Figure 6-16).
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 6-16).
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.
6.4.2.5  Chassis Assembly/Re-assembly
1.Replace the battery contact seal (if necessary) surrounding the battery contact (Figure 6-17).
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 6-17).
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.
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.Figure 6-16.  Keyboard Retainer Re-assembly
Note:
Be sure the battery contact seal protrudes through the chassis and is not pinched under the
chassis. 
						

							6881096C24-AAugust, 2004
Full Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General 6-13
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 being held by the top and bottom chassis groves.
.
6.4.2.6  Chassis and Front Cover Re-assembly
1.Dress and connect the speaker wires..
a. Connect the speaker wire assembly into the 2-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 6-18). 
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 6-18).
c. Slide the audio jack shroud onto accessory connector (Figure 6-17). Figure 6-17.  Main Board onto Chassis Re-assembly
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
Flex Cable Connector
Battery Contact Seal
Interface Pad
Frequency & 
Volume SwitchesAudio Jack Shroud
(Replace after Plugging
in Speaker and Mic)
O-Ring 
						

							July, 20046881096C24-A
6-14Full Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General
2.Position the radio (Figure 6-19), and reconnect the flex connector from the keyboard into the con-
nector located on the bottom of the main board, pushing up the 2 end tabs.
3.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, between shroud and housing.
4.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.Figure 6-18.  Microphone and Speaker Wires Re-assembly
Figure 6-19.  Keyboard Flex Cable Connection
Speaker Connector
Microphone
Connector
Shroud
Flex Cable Connector
Radio Chassis
End Tabs 
						

							6881096C24-A     July, 2004
Full Keypad Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General 6-15
5.Snap chassis assembly completely into the top of the front cover ( Figure 6-20) until it settles in 
place.
6. Make sure the 0-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.
7. Snap the bottom of the chassis into the front cover.
8. Check that O-ring is visible at the corners.
9. Re-assemble the knobs, antenna, and battery.
6.4.2.7  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 6-21a).
3. Press the PTT assembly against the front cover opening ( Figure 6-21b).
Figure 6-20.  Fastening the Chassis
Figure 6-21.  PTT Re-assembly
Radio Chassis
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. 
						

							August, 20046881096C24-A
6-16Full Keypad Model Disassembly and Re-assembly: Mechanical View and Parts List
6.5 Mechanical View and Parts List
6.5.1 PR400 Full-Keypad Exploded View and Parts List
Figure 6-22.  PR400 Full Keypad Radio Exploded View
1
2829 3132 33
2
3
4
5
6
78
9
1011
12
13
14
15
16
17
18
19
20
21 22 23 25 26 27
30 
						

							Mechanical View and Parts List6-17
6881096C24-AAugust, 2004
ItemMotorola
Part
NumberDescription
1See Appendix 
AAntenna
2 3680530Z02 Knob, Frequency
31386440Z03Escutcheon, Top; 64 Ch.
4 5886627Z01 Antenna Adaptor/Seal 
(Optional)
51586391Z03Housing, Full, with Lens
6 3586621Z01 Speaker, Felt
73886489Z01PTT, Rubber
8 4586439Z01 PTT, Plastic
90186638Z01Speaker Assembly
10 4286620Z01 Retainer Speaker
113586621Z02Felt, Microphone
12 0780608V01 Boot, Microphone
130186639Z01Microphone Plug Assembly
14 5104949J16 Display, LCD Module
150104017J18Keypad Board Assy
16 1586437Z01 Shroud, Audio Jack
173286431Z05Seal, Main O-ring
18 7586436Z02 Pad, PA Interface
192786389Z02Chassis
20 3286435Z01 Seal, Battery Contact Block
210304726J05Screws, Chassis; 4 Used
22 4286648Z01 Plate, Retainer
238486617Z0128-Pin, Flex
25 7586654Z03 Keypad, Full
265586445Z02Latch Assembly
27 4105944K01 Spring, Latch; 2 Used
283886441Z01Cap, Dust
29 3286432Z01 Seal, Control Shaft
300386434Z01Screw, Speaker Retainer
31 3386443Z01 Label, Escutcheon Seal
326186446Z02Lightpipe
33 3680529Z01 Knob, Volume
NON-REFERENCED ITEMS
3386625Z01 Nameplate, Motorola
ItemMotorola
Part
NumberDescription 
						

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6-18Full Keypad Model Disassembly and Re-assembly: Mechanical View and Parts List 
						

							Chapter 7 Limited Keypad Model Disassembly and
Re-assembly
7.1 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
7.2 Preventive Maintenance
The radios do not require a scheduled preventive maintenance program; however, periodic visual 
inspection and cleaning is recommended.
7.2.1 Inspection
Check that the external surfaces of the radio are clean, and that all external controls and switches are 
functional. It is not recommended to inspect the interior electronic circuitry.
7.2.2 Cleaning Procedures
The following procedures describe the recommended cleaning agents and the methods to be used 
when cleaning the external and internal surfaces of the radio. External surfaces include the front 
cover, housing assembly and battery case. These surfaces should be cleaned whenever a periodic 
visual inspection reveals the presence of smudges, grease, and/or grime. 
The only recommended agent for cleaning the external radio surfaces is a 0.5% solution of a mild 
dishwashing detergent in water. The only factory recommended liquid for cleaning the printed circuit 
boards and their components is isopropyl alcohol (70% by volume).
Cleaning External Plastic Surfaces
Apply the 0.5% detergent-water solution sparingly with a stiff, non-metallic, short-bristled brush to 
work all loose dirt away from the radio. Use a soft, absorbent, lintless cloth or tissue to remove the 
solution and dry the radio. Make sure that no water remains entrapped near the connectors, cracks, or 
crevices.Note:
Internal surfaces should be cleaned only when the radio is disassembled for service 
or repair.
CAUTION: The effects of certain chemicals and their vapors can have harmful results on certain plas-
tics. Avoid using aerosol sprays, tuner cleaners, and other chemicals.
! 
						

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7-2Limited 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 high-pressure air to hasten the drying process 
since this could cause the liquid to collect in unwanted places. After completing the cleaning process, 
use a soft, absorbent, lintless cloth to dry the area. Do not brush or apply any isopropyl alcohol to the 
frame, front cover, or back cover.
7.3 Safe Handling of CMOS and LDMOS Devices
Complementary metal-oxide semiconductor (CMOS) devices are used in this family of radios, and are 
susceptible to damage by electrostatic or high voltage charges. Damage can be latent, resulting in 
failures occurring weeks or months later. Therefore, special precautions must be taken to prevent 
device damage during disassembly, troubleshooting, and repair. 
Handling precautions are mandatory for CMOS circuits and are especially important in low humidity 
conditions. DO NOT attempt to disassemble the radio without first referring to the following CAUTION 
statement.  Note:
Always use a fresh supply of alcohol and a clean container to prevent contamination by 
dissolved material (from previous usage).
CAUTION: This radio contains static-sensitive devices. Do not open the radio unless you are properly 
grounded. Take the following precautions when working on this unit:
 Store and transport all CMOS devices in conductive material so that all exposed 
leads are shorted together. Do not insert CMOS devices into conventional plastic 
“snow” trays used for storage and transportation of other semiconductor devices.
 Ground the working surface of the service bench to protect the CMOS device. We 
recommend using the Motorola Static Protection Assembly (part number 
0180386A82), which includes a wrist strap, two ground cords, a table mat, and a 
floor mat.
 Wear a conductive wrist strap in series with a 100k resistor to ground. (Replacement 
wrist straps that connect to the bench top covering are Motorola part number RSX-
4015.)
 Do not wear nylon clothing while handling CMOS devices.
 Do not insert or remove CMOS devices with power applied. Check all power 
supplies used for testing CMOS devices to be certain that there are no voltage 
transients present.
 When straightening CMOS pins, provide ground straps for the apparatus used.
 When soldering, use a grounded soldering iron.
 If at all possible, handle CMOS devices by the package and not by the leads. Prior 
to touching the unit, touch an electrical ground to remove any static charge that you 
may have accumulated. The package and substrate may be electrically common. If 
so, the reaction of a discharge to the case would cause the same damage as 
touching the leads.!