Panasonic KX-T7730X User manual

ORDERNO. KMS0110592C3
PROPRIETARYTELEPHONE
KX-T7730X
(forAsia, MiddleNearEast, Africa and LatinAmerica)
SPECIFICATIONS
1. INTRODUCTION
1.1. NOTE
Whenyou notetheserial number, writedownall ofthe11 digits.
1

Theserial numbermay befound on thelabel affixedtothebottom oftheunit.
1.2. FORSERVICETECHNICIANS
ICsand LSIsarevulnerabletostaticelectricity.
Whenrepairing, thefollowing precautionswill helppreventrecurring malfunctions.
1. Covertheplasticparts boxes withaluminumfoil.
2. Ground thesoldering irons.
3. Use aconductivemat on theworktable.
4. DonottouchICorLSI pinswithbarefingers.
2. LOCATIONOFCONTROLS
2

3

3. CONNECTION
Caution:
Ensurethecordisinsertedinthegroovetopreventdamagetothe
connector.
4. DISASSEMBLYINSTRUCTIONS
4

1. Remove theStand.
2. Remove 4Screws(A).
3. Remove theBottom Cabinet.
4. Remove theConnector (1~3)and theFlatCable
from theMainBoard.
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5. Remove 2Screws(A).
6. Remove theMainBoard from theTop Cabinet.
7. Remove theCablefrom theMainBoard.
8. Remove theLCD Holderbysliding theHookinthe
direction ofthearrowfrom theMainBoard.
5. ICDATA
6

PinNo. Terminal
Name I/OFunction I/OSetting Description
1RE0 I I LCD linageH:3lineModel L:Other
2TEST I - Vcc Connection
3OSC1 I - 4MHz
4OSC2 O - 4MHz
5RESET I -
6X1 I - NotusedVcc Connection
7X2 O - Open
8GND - -
9D0 I/O OHS SMmute
10 D1 I/O OHFMM mute
11 D2 I/O O(I) HFSMmute(Thisisalsomodel code.)
12 D3 I/O OHFRelay
13 D4 I/O OHS poweron
14 D5 I/O OHFpoweron (CS)
15 D9 I/O IHOLDKey L:Key press
16 D10 I/O ODO
17 D11 I/O ODCLR
18 D12 I I DI
19 D13 I I DI_INT
20 R00 I/O IKEY-IN0
21 R01 I/O IKEY-IN1
22 R02 I/O IKEY-IN2
23 R03 I/O IKEY-IN3
24 R10 I/O IKEY-IN4
25 R11 I/O IKEY-IN5
26 R12 I/O IKEY-IN6
27 R13 I/O IHook-SW
28 R20 I/O OKEY/LED-COM0
29 R21 I/O OKEY/LED-COM1
30 R22 I/O OKEY/LED-COM2
31 R23 I/O OKEY/LED-COM3
32 R30 I/O I/O KEY-COM4
33 R33 I/O O(I) LCD_Contrast1(Thisisalsomodel
code.)
34 R32 I/O O *LCD_Contrast0
35 R31 I/O I/O KEY-COM5
36 R40 I/O IRing vol off
37 R41 I/O O LCD_CLK
38 R42 I/O O(I) LCD_STB/(Model Code)
39 R43 I/O O LCD_DO
40 R60 I/O O LED0
41
R61
I
/
O
O
LED1
7

41
R61
I
/
O
O
LED1
PinNo. Terminal
Name I/OFunction I/OSetting Description
42 R62 I/O O LED2
43 R63 I/O O LED3
44 R70 I/O O LED4
45 R71 I/O O LED5
46 R72 I/O O LED6
47 R73 I/O O LED7
48 R80 I/O OHFSP vol 1
49 R81 I/O OHFSP vol 2
50 R82 I/O OHFSP vol 3
51 R83 I/O OHFSP vol 4
52 R90 I/O OTonecont1
53 R91 I/O OTonecont2
54 R92 I/O OTonecont3
55 R93 I/O OTonecont4
56 RA0 I/O OHS SP vol 1
57 RA1 I/O OHS SP vol 2
58 SEL I I AFour-minuteCycleVcc Connection
59 VCC - -
60 TONC O O DTMFColumn
61 TONR O O DTMFRow
62 VTref - - DTMFStandard Power
63 RD0 I I HeadSetDetention
64 RD1 I I TONE-DET
6. BLOCK DIAGRAM
7. CIRCUITOPERATIONS
7.1. KEYINPUTCONTROLCIRCUIT
Sequential inputinformation isexecutedbydynamicscanning.
TheportsR20~R23, R30, R31 ofIC1arebroughttohigh statusconsecutively.
Ifakey ispressed, thekey-ininformation inputisexecutedbyportsR00~R03, R10~R13.
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7.2. LEDCIRCUIT
CircuitOperation:
TheLEDexecutes dynamiclighting for thestatusindicators, and control isexecutedbythe
outputportsR20~R23, R60~R63, R70~R73.
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7.3. DATACOMMUNICATIONCIRCUIT
Function:
Thedatacommunication circuitserves thefollowing functions:
Information exchangerbetweenthePBX and proprietarytelephone, key inputinformation as well
as datafor theLEDcontrol, LCD control, etc. Thisinformation iscontinuouslyexchangedatall
times.
CircuitOperation:
Whentheproprietarytelephonereceives anIRQsignal from thePBX and aftersending thekey
inputinformation (19 pulses)tothePBX and receiving data(47 pulses)for theLEDcontrol, etc.,
theproprietarytelephonewill return tothePBX anacknowledgesignal.
1)Reception
Thedatafrom thePBX isreceivedviatheHand Llines along thepathshownbelow.
H, LLineD2T2R106 Q102 IC2IC1Pin18
2)Transmission
Thedatatotheproprietarytelephoneistransmittedalong thefollowing path.
IC1Pin16 IC2Q101 T2D2H, LLine
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7.4. TONEGENERATIONCIRCUIT
Function:
Thiscircuitgenerates all system tones including COL, extension, busy, DTMFsignalsand key in
confirmation tones during thepowerfailuremodeand iscomprisedofIC1(DTMFGenerator)and
IC5(Analog Switch).
CircuitOperation:
For anoutputofasinglerowtone, therowterminal and theeachcolumnterminalsintersecting
withitarerequiredtobebroughtalowstate. For adual toneoutput, onerowterminal and one
columnterminal arebroughttolowstate.
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CONDITION IC1pin52 IC5SWA IC1pin53 IC5SWB IC1pin54 IC5SWC IC1pin55
IC5
SWD
Ringing L OFF L OFF L OFF H
ON
Call Waiting L OFF L OFF H ON L
OFF
ToneDial (Handset) HON HON LOFF L
OFF
ToneDial
(Speakerphone) HON LOFF H ON L
OFF
7.5. HANDSETCIRCUIT
1)Transmission Signal Path
Theinputsignal for thehandsetmicrophoneissentthrough thetelephonelineviathefollowing
path:
HandsetMIC(JK2)JK3C24 R26 C34 Q5C21 R21 Q3C4T1
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C3Q1D1TelephoneLine
2)Reception Signal Path
Theinputsignal from thetelephonelineissenttothereceiverthrough thefollowing path:
TelephoneLineD1Q1C3T1C4Q3R10 C8R12 Q4C26
R32 IC10 C32 R34 C27 R208 Q8C31 JK3JK2HandsetSpeaker
7.6. SPEAKERPHONECIRCUIT
Function:
Thiscircuitcontrolstheautomaticswitching ofthetransmittedand receivedsignalstoand from
thetelephoneline, whentheunitisusedinthehands-free mode.
CircuitOperation:
Thespeakerphonecanonlyprovideaone-way communication pathatagiventime, butcannot
do bothsimultaneously.
Therefore, aswitching circuitisnecessarytocontrol theflowoftheoutgoing and incoming
signals.
Inotherwords, itcaneithertransmitanoutgoing signal or receive anincoming signal atagiven
time, butcannotdo bothsimuitaneousiy. Therefore, aswitching circuitisnecessarytocontrol
theflowoftheoutgoing and incoming signals.
Thisswitching circuitiscontainedinIC3and consistsofaVoice Detector, TxAttenuator, Rx
Attenuator, Comparator and Attenuator Control. Thecircuitanalyzes whethertheTx(transmit) or
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Rx(receive)signal islouder, and thenitprocesses thesignalssothattheloudersignal isgiven
precedence.
TheVoice Detector provides aDC inputtotheAttenuator Control corresponding totheTxsignal.
TheComparator receives aTxand Rxsignal, and supplies DC inputtotheAttenuator Control
corresponding totheRxsignal.
TheAttenuator Control provides acontrol signal totheTxand RxAttenuator toswitchthe
appropriatesignalsONand OFF.
TheAttenuator Control alsodetectsthelevel ofthevolumecontrol toautomaticallyadjustthe
volumefor changing ambientconditions.
1)Control Signal Path
Control signal for transmission and reception areinputtoIC3viathefollowing path:
(Transmission Control Signal Path)
MIC(CN2)IC3Pin9IC3Pin10 IC3Pin3IC3Pin4IC3Pin5
(Reception Control Signal Path)
TelephoneLineQ3Q4IC3Pin7
2)Transmission/Reception Switching
Thecomparison resultbetweenTxand RxoutputisaDC level atIC3Pin26.
Txlevel ishigh .................... Pin21-Pin26=6mV
Rxlevel ishigh .................... Pin21-Pin26=150mV
Thecomparator outputisconnectedtotheattenuator control insideIC3.
3)Voice Detector
Theoutputofthemicamp(Pin10 ofIC3)issuppliedtoPin14 ofIC3as acontrol signal for the
voice detector.
4)Attenuator Control
Theattenuator control detectsthesetting ofthevolumecontrol through Pin25 ofIC3and
automaticallyadjuststhevolumefor changing ambientconditions.
5)Transmission Signal Path
Theinputsignal from themicrophoneissentthrough thecircuitviathefollowing path:
MIC(CN2)C64 R206 C59 IC3Pin9IC3Pin10 R45 C48 IC3Pin3IC3
Pin4C41 R41 Q3C4T1C3Q1D1JK1TelephoneLine
6)Reception Signal Path
Signalsreceivedfrom thetelephonelineareoutputtothespeakerviathefollowing path:
TelephoneLineD1Q1C3T1C4Q3R10 C8R12 Q4C42
R42 C46 IC3Pin29 IC3Pin28 R57 C62 C61 IC3Pin20 IC3Pin16
C63 CN3Speaker
7)Busy ToneDetector Circuit
Thebusy tonedetection for automaticredealing isexecutedas follows.
TelephoneLineD1Q1C3T1C91 R91 IC6D3R99 Q20 IC1
Pin64
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8. TROUBLESHOOTING GUIDE
8.1. NO OPERATION
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8.2. HANDSETTROUBLE
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8.3. SPEAKER-PHONETROUBLE
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8.4. TONEDIALTORUBLE
8.5. THEELECTRONICVOLUMEOFTHESPEAKER-PHONEDOES
NOTWORK
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8.6. THEELECTRONICVOLUMEOFHANDSETDOES NOTWORK
9. TERMINALGUIDE OFICS, TRANSISTORS AND
DIODES
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10. HOWTO REPLACE THE FLATPACKAGEIC
Ifyou do nothave thespecial tools(for example:SPOTHEATER) toremove theSPOTHEATER’S
FlatIC, Ifyou have solder(largeamount) asoldering iron and acutterknife, you caneasily
remove IC’seventhough largethan100 pin.
10.1. PREPARATION
-SOLDER/ SparkleSolder115A-1, 115B-1 orAlmitSolderKR-19, KR-
19RMA
-Soldering iron / Recommendedpowerconsumption isbetween30
Wto40 W. / TemperatureofCopperRod 662 ±50°F(350 ±10°C)/
(Anexpertmayhandlea60~80 Wiron, butbeginnermightdamage
foil byoverheating.)
-Flux/ HI115 Specificgravity0.863 / (Original fluxshouldbe
replaceddaily.)
10.2. FLATPACKAGEICREMOVE PROCEDURE
1. Whenall oftheICleadcannotbeenseenat thestandarddegree,
fill withlargequantities ofsolder.
Note:
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