Motorola Portable Radio Ep450 Basic Hkln4215a Manual

							December 3, 2003HKLN4215A
6-6Display 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.  Dust Cover Disassembly
6.4.1.3  Speaker and Microphone Disassembly 
1.Remove the screw from the speaker retainer using a T6 Torx screwdriver (Figure 6-7.
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 6-7.  Removal Speaker-Microphone Assembly
c. Separate dust b. Rotate dust cover 90° to
a. Pry dust cover from body.
key
allow key to be removed.cover from body.
Retainer Bracket
Radio Housing
Speaker
Speaker Connector
Microphone Connector
Microphone 
						

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Display Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General 6-7
6.4.1.4  Keyboard Removal
1.Carefully pry the four keypad retainer locking tabs free from the housing use a scribe.
2.Lift the keypad retainer up from the bottom and slide the top tabs out.
3.Slide keypad retainer out of chassis 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 Disassembly
1.If required, the PTT (Figure 6-9 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. Note:
Use care when removing the keypad retainer to prevent damage to the keyboard flex cable.
CAUTION:  Refer to the CMOS CAUTION paragraph (6.3) before removing the main board. Be sure to 
use Electrostatic Discharge protection when handling circuit boards.
Figure 6-8.  Keypad Removal
!
Keypad
Keypad Retainer
Flex Cable
Keypad Board 
						

							December 3, 2003HKLN4215A
6-8Display 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 protection when handling circuit boards.
Figure 6-10.  Removal of Main Board from Chassis
Flat BladeScrewdriver
PTT Seal
Ta b
Ta b
Hooks
!
Main Board
Radio Chassis
Audio Jack Shroud
O-Ring 
						

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Display Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General 6-9
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 cap is seated properly onto the recess.
4.Press the cap again to ensure it fully covers the opening for the audio jack.
.
6.4.2.2  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.
3.3. Insert the Boot and microphone sub-assembly into the microphone recess in the housing and 
route wires as shown in Figure 6-12. Note:
Make sure the dust cap is placed between the keypad retainer mounting post and the side
wall of the radio.
Figure 6-11.  Dust Cap Re-assembly
12 34 
						

							December 3, 2003HKLN4215A
6-10Display 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 - 2.5 lb/in.Figure 6-12.  Microphone Re-assembly
Note:
Make sure the speaker and microphone wires are routed tightly between the speaker basket
and the housing post.
Figure 6-13.  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
Ta b  O p e n i n g
Speaker Tab 
						

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Display 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 
						

							December 3, 2003HKLN4215A
6-12Display 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.Replace the O-ring by positioning it 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.
6.Check that the O-ring is not twisted and being held by the top and bottom chassis groves.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. 
						

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Display Model Disassembly and Re-assembly: Disassembling and Re-assembling the Radio — General 6-13
.
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 
						

							December 3, 2003HKLN4215A
6-14Display 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 
						

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Display 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.After closing the radio, verify that the O-ring is not visible; if visible, re-assemble properly.
10.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.