Panasonic KX-TS2388RUB User manual

© Panasonic System Networks Co., Ltd. 2010
Unauthorized copying and distribution is a violation
of law.
ORDER NO. KM41010283CE
Telephone Equipment
Model No. KX-TS2388RUB
KX-TS2388RUW
KX-TS2388CAB
KX-TS2388CAW
KX-TS2388UAB
KX-TS2388UAW
Integrated Telephone System
B: Black Version
W: White Version
(for Russia, Central Asia and Ukraine)

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KX-TS2388RUB/KX-TS2388RUW/KX-TS2388CAB/KX-TS2388CAW/KX-TS2388UAB/KX-TS2388UAW
WARNING
This service information is designed for experienced repair technicians only and is not designed for use by the general
public. It does not contain warnings or cautions to advise non-technical individuals of potential dangers in attempting
to service a product. Products powered by electricity should be serviced or repaired only by experienced professional
technicians. Any attempt to service or repair the product or products dealt with in this service information by anyone
else could result in serious injury or death.
IMPORTANT SAFETY NOTICE
There are special components used in this equipment which are important for safety. These parts are marked by
in the Schematic Diagrams, Circuit Board Diagrams, Exploded Views and Replacement Parts List. It is essential that
these critical parts should be replaced with manufacturer's specified parts to prevent shock, fire or other hazards.
Do not modify the original design without permission of manufacturer.
IMPORTANT INFORMATION ABOUT LEAD FREE, (PbF), SOLDERING
If lead free solder was used in the manufacture of this product, the printed circuit boards will be marked PbF.
Standard leaded, (Pb), solder can be used as usual on boards without the PbF mark.
When this mark does appear, please read and follow the special instructions described in this manual on the
use of PbF and how it might be permissible to use Pb solder during service and repair work.
LWhen you note the serial number, write down all 11 digits. The serial number may be found on the bottom of the unit.
LThe illustrations in this Service Manual may vary slightly from the actual product.

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KX-TS2388RUB/KX-TS2388RUW/KX-TS2388CAB/KX-TS2388CAW/KX-TS2388UAB/KX-TS2388UAW
TABLE OF CONTENTS
PAGE PAGE
1 Safety Precautions----------------------------------------------- 4
1.1. For Service Technicians --------------------------------- 4
2 Warning -------------------------------------------------------------- 4
2.1. Battery Caution--------------------------------------------- 4
2.2. About Lead Free Solder (Pbf: Pb free)--------------- 4
2.3. Discarding of P. C. Board-------------------------------- 5
3 Specifications ----------------------------------------------------- 6
4 Technical Descriptions ----------------------------------------- 7
4.1. Block Diagram---------------------------------------------- 7
4.2. Circuit Operation------------------------------------------- 8
5 Location of Controls and Components ------------------12
6 Installation Instructions ---------------------------------------12
7 Operating Instructions-----------------------------------------12
7.1. For Service Hint-------------------------------------------12
8 Troubleshooting Guide ----------------------------------------13
8.1. Service Hints-----------------------------------------------13
8.2. Pulse Dialing Problems ---------------------------------13
8.3. Tone Dialing Problems ----------------------------------14
8.4. No Ringing Sound When Ring Signal is Input ----14
9 Disassembly and Assembly Instructions ---------------15
9.1. Disassembly Instructions -------------------------------15
9.2. Assembly Instruction-------------------------------------17
10 Miscellaneous ----------------------------------------------------21
10.1. IC Block diagram -----------------------------------------21
10.2. How to Replace the Flat Package IC ----------------25
10.3. Terminal Guide of the ICs, Transistors and
Diodes -------------------------------------------------------27
11 Schematic Diagram ---------------------------------------------28
11.1. For Schematic Diagram---------------------------------28
11.2. Schematic Diagram (Main)-----------------------------30
11.3. Schematic Diagram (Operation) ----------------------32
12 Printed Circuit Board-------------------------------------------35
12.1. Circuit Board (Main)--------------------------------------35
12.2. Circuit Board (Operation) -------------------------------37
13 Exploded View and Replacement Parts List -----------39
13.1. Cabinet and Electrical Parts ---------------------------39
13.2. Accessories -----------------------------------------------40
13.3. Replacement Part List-----------------------------------41

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KX-TS2388RUB/KX-TS2388RUW/KX-TS2388CAB/KX-TS2388CAW/KX-TS2388UAB/KX-TS2388UAW
1 Safety Precautions
1.1. For Service Technicians
•Repair service shall be provided in accordance with repair technology information such as service manual so as to pre-
vent fires, injury or electric shock, which can be caused by improper repair work.
1. When repair services are provided, neither the products nor their parts or members shall be remodeled.
2. If a lead wire assembly is supplied as a repair part, the lead wire assembly shall be replaced.
3. FASTON terminals shall be plugged straight in and unplugged straight out.
•ICs and LSIs are vulnerable to static electricity.
When repairing, the following precautions will help prevent recurring malfunctions.
1. Cover plastic parts boxes with aluminum foil.
2. Ground the soldering irons.
3. Use a conductive mat on worktable.
4. Do not grasp IC or LSI pins with bare fingers.
2Warning
2.1. Battery Caution
1. Danger of explosion if battery is incorrectly replaced.
2. Replace only with the same or equivalent type recommended by the manufacturer.
3. Dispose of used batteries according to the manufacturer's Instructions.
2.2. About Lead Free Solder (Pbf: Pb free)
Note:
In the information below, Pb, the symbol for lead in the periodic table of elements, will refer to standard solder or solder that con-
tains lead.
We will use PbF solder when discussing the lead free solder used in our manufacturing process which is made from Tin (Sn),
Silver (Ag), and Copper (Cu).
This model, and others like it, manufactured using lead free solder will have PbF stamped on the PCB. For service and repair
work we suggest using the same type of solder.
Caution
• PbF solder has a melting point that is 50 F ~ 70 F (30 C ~ 40 C) higher than Pb solder. Please use a soldering iron with tem-
perature control and adjust it to 700 F ± 20 F (370 C ± 10 C).
• Exercise care while using higher temperature soldering irons.:
Do not heat the PCB for too long time in order to prevent solder splash or damage to the PCB.
• PbF solder will tend to splash if it is heated much higher than its melting point, approximately 1100 F (600 C).
• When applying PbF solder to double layered boards, please check the component side for excess which may flow onto the
opposite side (See the figure below).
component
component
pin
solder
remove all of the
excess solder
slice view

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KX-TS2388RUB/KX-TS2388RUW/KX-TS2388CAB/KX-TS2388CAW/KX-TS2388UAB/KX-TS2388UAW
2.2.1. Suggested PbF Solder
There are several types of PbF solder available commercially. While this product is manufactured using Tin, Silver, and Copper
(Sn+Ag+Cu), you can also use Tin and Copper (Sn+Cu) or Tin, Zinc, and Bismuth (Sn+Zn+Bi). Please check the manufac
turer's specific instructions for the melting points of their products and any precautions for using their product with other materi-
als. The following lead free (PbF) solder wire sizes are recommended for service of this product: 0.3 mm, 0.6 mm and 1.0 mm.
2.3. Discarding of P. C. Board
When discarding P. C. Board, delete all personal information such as telephone directory and caller list or scrap P. C. Board.
0.3mm X 100g 0.6mm X 100g 1.0mm X 100g

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KX-TS2388RUB/KX-TS2388RUW/KX-TS2388CAB/KX-TS2388CAW/KX-TS2388UAB/KX-TS2388UAW
3 Specifications
Note:
• Design and specifications are subject to change without notice.
Power Source: From telephone line
From 3 AA (LR6, R6, UM-3) batteries
Memory Capacity: 50 Caller ID memory, 50 Directory memory.
Redial: The unit redials the last dialed number
Microphone: Electret condenser microphone
Input Jack: Telephone Line
Approx. 93 mm x 172 mm x 220 mmDimensions (H x W x D):
Mass (weight): Approx. 550
Operating Enviroment: 0 oC - 40 oC, 20 % - 80 % relative air humidity (dry)
g
Speaker Unit: Unit: 5.7cm (2.5") PM magnetic type 32
Handset: 3 cm (113/16") PM dynamic type 150

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KX-TS2388RUB/KX-TS2388RUW/KX-TS2388CAB/KX-TS2388CAW/KX-TS2388UAB/KX-TS2388UAW
4 Technical Descriptions
4.1. Block Diagram
1R5D,3D1CP1
TP
S
D1
C1
MIC (2AP)
6D,4D1CI
D601
Q107 Q101, Q103 D101 T
IC601
Handset/Headset
R
SP
MIC
Q108
IC201, Q201
D302
Q110
D301
IC871 IC302
IC831 1AP PCB D505
IC861
IC651
4.5V
2AP PCB IC501, Q501, Q502 Battery
LCD
KX-TS880 / TS2388 Series : BLOCK DIAGRAM
Q422
Q401, Q402, Q403
IC801
MICON
Ringer indication LED
LED1 (Small PCB)
JOHN SMITH
1234567890
RINGER
IC
INUSE / EXHOOK
Line
ON/OFF
Handset Receiving
Amp
EEPROM
128K
TIPIN
Sidetone
Bridge
RESET
BATTLOW
Reset IC
2.7V
Handset
Sending
Amp
Keyboard
Switch
RINGIN
Battery Low
Detector
Regulator
3.3 V
FSK / DTMF Circuit
Wakeup Circuit
WAKE UP
Dummy Ringer
Circuit
SP-Phone
Circuit
Expander
I/O IC
DRIN
G
DTMF
Dial Tone
Detect
Ex-Hook
Detect
TONE_DET
In Use Detect
PGAIN2
RING_DET
D801

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4.2. Circuit Operation
4.2.1. Bell Detector Circuit
When the bell signal is input from LINE to T/R (when the telephone rings), the signal is output at the speaker via the following
path :
T/R R1/C1 D1/LED1 (small PCB) D3/D4 IC1 (pin8) IC1 (pin5) PC1 C5 SW2 (R7/R8/R9)T1 Speaker
4.2.2. Dummy Ringer Circuit
When {AOH}button is pressed during incoming call (Caller ID AOH mode), dummy ring function will be activated.
The bell signal from LINE stops and Caller ID is received.
Set will keep on ringing by the dummy ring function until the handset is picked up / speakerphone is on.
The dummy ring signal is generated from IC801 via the following path :
(Speakerphone will be activated during dummy ring)
IC801 (pin 89)R901 Q2 SW2 ( R11/R12/R13 ) C8 R615 C616 IC601 (pin 19) IC601 (pin 15)C618 
Speaker
4.2.3. Telephone Line Interface
4.2.3.1. Circuit operation
•On hook
Q101 is OFF, on-hook condition where DC loop is disconnected and voice signal flow is cut.
•Off hook
During Off-Hook, pin 1_3 of SW101 and Q101 is ON, providing an off-hook condition (active DC current flow through the circuit)
and the following is the signal flow :
T POS101 L101 D101(+) Q101 R180 Q107 R119 D103 D101(-) L102 R
•Receiving signal flows:
LINE Q101 R180 C109 C401 R401 L412 L401 Q401 C404 R405 R417 L405 C405 L406
Q402 C408 R413 L409 Q403 C410 VR401 SP (handset)
•Transmission signal flows:
MIC (handset) C422 VR402 R423 C425 L421 R430 Q422 R429 C429 L107 Q107 Q101 
R180 LINE
•Pulse Dial
A pulse signal switches repeatedly between high and low logic is output from IC801 (pin 73), on and off the line loop, generating
the pulse dial signal.

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KX-TS2388RUB/KX-TS2388RUW/KX-TS2388CAB/KX-TS2388CAW/KX-TS2388UAB/KX-TS2388UAW
4.2.4. Speakerphone Circuit
4.2.4.1. Function
The circuit controls the automatic switching of the transmitted and received signals, to and from the telephone line, when the
unit is used in the hands -free mode.
4.2.4.2. Circuit Operation
The speakerphone can only provide a one-way communication path.
In other words, it can either transmit an outgoing signal or receive an incoming signal at a given time, but cannot do both simul-
taneously. Therefore, a switching circuit is necessary to control the flow of the outgoing and incoming signals.
This switching circuit is contained in IC601 and consists of a Voice Detector, TX Attenuator, RX Attenuator, Comparator and
Attenuator Control. The circuit analyzes whether the TX(transmit) or the RX(receive) signal is louder, and then it processed the
signals such that the louder signal is given precedence.
The Voice Detector provides a DC input to the Attenuator Control corresponding to the TX signal.
The Comparator receives a TX and a RX signal, and supplies a DC input to the Attenuator Control corresponding to the RX sig-
nal.
The Attenuator Control provides a control signal to the TX and the RX attenuator to switch the appropriate signals on and off.
The Attenuator Control also detects the level of the volume control to automatically adjust for changing ambient conditions.
1. Transmission signal path:
The input signal from the microphone is sent through the circuit via the following path: MIC Pin 9 of IC601 Pin 10 of
IC601 Pin 3 of IC601 Pin 4 of IC601 R601 C602 L107 Q107 Tel line.
2. Reception signal path:
Signals receive from the telephone line are outputted at the speaker via the following path: Tel line Q107 Q401 C404
R600 C603 Pin 27 of IC601 Pin 26 of IC601 Pin 19 of IC601 Pin 15 of IC601 Speaker.
3. Transmission/Reception switching
The comparison result between TX and RX outputs as a DC level of Pin 25 of IC601. TX level is high ...... Pin 25 = Pin 21 -
6mV RX level is high ...... Pin 25 = Pin 21 - 150mVComparator output is connected to the attenuator control inside of IC601.
4. Voice detector
The output of the mic amp (Pin 10 of IC601) is supplied to Pin 13 of IC601 as a control signal for the voice detector.
5. Attenuator control
The attenuator control detects the setting of the volume control through Pin 24 of IC601 to automatically adjust for changing
ambient conditions.

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KX-TS2388RUB/KX-TS2388RUW/KX-TS2388CAB/KX-TS2388CAW/KX-TS2388UAB/KX-TS2388UAW
4.2.5. Initializing Circuit
4.2.5.1. Function
This circuit is used to initialize the CPU when the batteries are installed.
4.2.5.2. Circuit Operation
When the batteries is inserted into the unit, then the voltage is regulated by IC302 and power is supplied to the CPU. The set
can operate in the circuit voltage diagram.
Regulator
(1AP PCB)
Reset Circuit
(2AP PCB)
IC302
1
VIN
2
GND
4
NC
5
VOUT
3
STBY
C301
Battery 4.5V
C302
C304
C303
D301
C864
IC861
1
VOUT
2
VCC
3
NC
4
GND
Q862
VCC
R863
R862
R833
R864
C862
Stop
Reset
Vcc
IC801 (105)
3.3V
3.3V
3.3V
IC801 (81)
IC801 (50)
Reset
CPU Reset
Stop
2.7 V

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4.2.6. Caller ID Detect Circuit
4.2.6.1. Function (FSK Signal)
The caller ID is a changeable ID which the user of a telephone circuit obtains by entering a contract with the telephone company to
utilize a caller ID service. For this reason, the operation of this circuit assumes that a caller ID service contract has been entered for
the circuit being used. The data for the caller ID from the telephone exchange is sent during the interval between the first and sec-
ond rings of the bell signal. The data from the telephone exchange is a modem signal which is modulated in an FSK (Frequency
Shift Keying) format. Data "0" is a 1200 Hz sine wave, and data “1” a 2200 Hz sine wave. There are two types of the message for-
mat which can be received: i.e. the single message format and plural message format. The plural message format allows to trans-
mit the name and data code information in addition to the time and telephone number data.
•FSK (Frequency Shift Keying) format
4.2.6.2. Circuit Operation
Caller ID signal is sent through the circuit via the following path :
LINE C500/C520 C551/C552 R551/R552 R553/R554 IC801 (pin 92, 93)
STD Ring / 20Hz
Tip-Ring
FSK DATA in
1st Ring Silent interval 2nd Ring
DATA
0.1Vrms
70Vrms
1300Hz or
1200Hz
=DATA "0"
2100Hz or
2200Hz
=DATA "1"

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KX-TS2388RUB/KX-TS2388RUW/KX-TS2388CAB/KX-TS2388CAW/KX-TS2388UAB/KX-TS2388UAW
5 Location of Controls and Components
Refer to the Operating Instructions.
Note:
You can download and refer to the Operating Instructions (Instruction book) on TSN Server.
6 Installation Instructions
Refer to the Operating Instructions.
Note:
You can download and refer to the Operating Instructions (Instruction book) on TSN Server.
7 Operating Instructions
Refer to the Operating Instructions.
Note:
You can download and refer to the Operating Instructions (Instruction book) on TSN Server.
7.1. For Service Hint
If the current password is forgotten, key in " *7000 " then {ENTER}at the change password menu and you will be able to
change the password. After you enter a new password, you will be able to cancel the dial lock.

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KX-TS2388RUB/KX-TS2388RUW/KX-TS2388CAB/KX-TS2388CAW/KX-TS2388UAB/KX-TS2388UAW
8 Troubleshooting Guide
8.1. Service Hints
8.2. Pulse Dialing Problems
Check IC801 (91), R481, R485.
Check IC801, X1.Dead.
Check Q401, Q402, Q403.Can't hear the voice from handset.
Check Q422, Q107.No voice transmit.
Can't tone dial.
Check D3, D4, D5, D6, IC1, Q1
Check Q101, Q103, Q104.
No rings.
Can't pulse dial.
Check Handset jack.Can't speak with the handset.
Check IC801, R407~R409, IC601, Q406, Q407,
C412~C414, R619~R621.
Can't change the volume for Handset or
Speakerphone.
Check IC801, Q107, Q401.No volume handset or speakerphone.
SYMPTOM CURE
Check C551, C552, R551, R552, D551~D554, IC801.Caller ID Function doesn't work.
Check around IC501, Q501, Q502.
Caller ID Function doesn't work. (DTMF)
Check IC201, Q201.
Can't auto redial.
Check Q110.
Can't hold.
Check IC601.
Can't speak with the speakerphone.
Can a pulse sound
be monitored?
Check TEL line Jack.
Do pulses
(3 Vp-p) appear
at Pin73 of IC801?
Do pulses
(0.6 Vp-p) appear
at base of Q103?
Does the voltage
across Tip (T) and
Ring (R) rapidly
switch between 48V
and 10V ?
YES
NO Check IC801,
X1.
NO
Check dial mode
in Pulse Dialing?
Change to
Pulse Dial
mode.
NO
Check Q104.
Check Q101 and
Q103.
NO
YES
YES
YES
YES
NO

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KX-TS2388RUB/KX-TS2388RUW/KX-TS2388CAB/KX-TS2388CAW/KX-TS2388UAB/KX-TS2388UAW
8.3. Tone Dialing Problems
8.4. No Ringing Sound When Ring Signal is Input
Does the DTMF signal
appear at base of Q422?
Does the DTMF signal
appear at Pin91 of IC801?
Can the DTMF sound
be monitored ?
YES
YES
NO
Check Q422, Q107.
Check C485, R487, R490,
C415, L411, L409 and
Q403.
Check R481, R485, R486,
R488, C483, VR481, L421
and R430.
NO
Check IC801 and X1.
NO
YES
Is the voltage across Pin 8 and Pin 2 of
Check the telephone line.
Check C1, R1, R2, D1,
D3~D6 and LED1.
Does a sine wave of approximately 60V
or more appear across Tip and Ring?
YES
NO
YES
Call the unit from another telephone.
Does the tone ringer output signal
appear across Pin 5 and Pin 2 of IC1?
NO
NO Check IC1, R3, R4, C3 and
C4.
YES
Check the Ringer SW2, PC1, C5 and T1
IC1 30 Vp-p?

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KX-TS2388RUB/KX-TS2388RUW/KX-TS2388CAB/KX-TS2388CAW/KX-TS2388UAB/KX-TS2388UAW
9 Disassembly and Assembly Instructions
9.1. Disassembly Instructions
1Press the catches (1) and rotate the stand in
the direction (2) to remove the Stand.
Note:
When the Stand is in Low position, the
screws can be taken out just as it is.
2Remove 5 Screws to remove the Cabinet Cover.
3Remove the Hook Button.
1
2
3Hook Button
25 Screws

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KX-TS2388RUB/KX-TS2388RUW/KX-TS2388CAB/KX-TS2388CAW/KX-TS2388UAB/KX-TS2388UAW
4Rem
LED P.C. Board and Tel Line Jack.
ove Main P.C. Board, then unhook the
5Remove the 3 screws to remove the speaker.
LED P.C. Board
Main P.C. Board
Speaker
3 screws
Speaker
Operation P.C. Board
5
Tel Line Jack
6Remove the 4 screws to remove the Operational P.C. Board.
4 screws
6

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9.2. Assembly Instruction
9.2.1. How to Replace the Base Unit LCD
Note:
• Make sure to cut the length of the rubber of the soldering iron to become 23mm to 25mm.
• Preheat the soldering iron for 10 minutes for the Rubber of Soldering Iron to reached around 180~200C.
• The illustrations are simplified in this page. They may differ from the actual product.
Peel off the arak tape at the front of P.C.board.
P. C. board
Arak Tape
1
Peel off the HSC (Heat Seal Connector) from
the P.C. board, in the direction of the arrow.
Use some IPA alcohol to gently remove glue
stain on the P.C. board.
P. C. board
LCD
3
2
P. C. board
P. C. board
Platform
Platform
Crystal
Side View
Note :
The platform height must be able
to protect crystal at the bottom of
the P.C.board..
(Crystal height = 2mm)
Turn over the P.C. board and place a platform
as shown to protect the crystal at the bottom
side of the P.C.board.

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KX-TS2388RUB/KX-TS2388RUW/KX-TS2388CAB/KX-TS2388CAW/KX-TS2388UAB/KX-TS2388UAW
Fit the heatseal of the new LCD.
New LCD
0.2 mm
0.2 mm
Horizontal Interval
Tolerance
Vertical Interval
Tolerance
OK
NG
NG
NG
(Horizontal interval tolerance is
more than 0.2 mm.)
(Vertical interval tolerance is
more than 0.2 mm.)
(Inclined)
If interval tolerance between
center lines is less than
0.2 mm, it is o.k.
4

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KX-TS2388RUB/KX-TS2388RUW/KX-TS2388CAB/KX-TS2388CAW/KX-TS2388UAB/KX-TS2388UAW
D
C
B
A
I
H
G
F
E
DCBA IHGFE
Heatweld with the tip of the soldering
iron for 10 seconds each position
(in case of 60W soldering iron) with
10kg pressure applied 9 times on
position (A)~(I), as shown below.
Replace back the arak tape.
6
Note :
Make sure copper part of solder jig is not
touch the new LCD which will cause burn.
Rubber of Soldering Iron
(Part No. PQZZ430PRB)
Tip of Soldering Iron
(Part No. PQZZ430PIR)
5
P. C. board
Arak Tape

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9.2.2. How to Install the Headset Cover
1
Then, install the headset cover rubber to lower
cabinet as shown.
Press the rubber harder to ensure rubber attach
firmly with headset cover sheet.
Separator
90°
Cover Sheet
Ta b
Install the headset cover sheet.
Before install, bend the tab
90° towards adhesive side.
Peel off the separator from the headset cover.
2
3
4
12
Cover Sheet
3
4Cover Rubber
2