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TL-HP90
3-4. PRINTED WIRING BOARDS – KEY SECTION –
1
2
KEY BOARD
A
1
MAIN BOARD
A
B
CN301
4
1
C
5
MAIN BOARD
B
CN401
10
D
14
E
S367
PGM
F
Note :
• X : parts extracted from the component side.
•
: Pattern from the side which enables seeing.
(The other layers' patterns are not indicated.)
•
: Connected with carbon pattern.
3
4
S451
TALK
S352
S351
2/ABC
1
S354
S355
4/GHI
5/JKL
S358
S359
7/PQRS
8/TUV
S362
S363
/TONE
0/OPER
S361
S357
S365
SPEED DIAL
FLASH
REDIAL/PAUSE
5
6
D251
D551
RINGER
POWER
S353
3/DEF
S356
6/MNO
S360
9/WXYZ
S364
#
S452
HOLD
D553
HOLD
1-681-411-
10
10
Note on Schematic Diagram: MAIN SECTION
7
• All capacitors are in µF unless otherwise noted. pF: µµF
50 WV or less are not indicated except for electrolytics
and tantalums.
• All resistors are in Ω and
specified.
•
: internal component.
f
• C : panel designation.
• U : B+ Line.
• Power voltage is dc 12V and fed with regulated dc power
supply from MJ101.
• Voltages and waveforms are dc with respect to ground
under no-signal conditions.
no mark : TALK OFF
(
) : TALK ON
• Voltages are taken with a VOM (Input impedance 10 MΩ).
Voltage variations may be noted due to normal produc-
tion tolerances.
• Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal produc-
tion tolerances.
• Circled numbers refer to waveforms.
• Signal path.
N
: RX
O
: TX
P
: bell
Waveforms
z
1
280nsec
IC301 8
VOLT/DIV : 1 V AC
OSCO
TIME/DIV : 0.2µsec
11
(11)
1
/
W or less unless otherwise
4
3.9Vp-p
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