Panasonic Va-208 Key Telephone System Installation Manual

Service Check Point-7 
No hold tone. . . . . In case of TEL A-K communication is normal 
(1) Does RL5 operates by the hold data from TEL? 
. . 
; 
22 I 
I 
23 I I 
IC4 
Does it output @ Dbes it operates on hold.? 
status on hold? Does it output 0 status? 
(2) Does it output the hold tone? 
In case of COLI hold. Does it output the 
hold tone? 
f 
Hold tone 
transmit circuit 
24 
1 2 
IC4 
I COL2 
25 
I 
I 
I 
I I : 
Does it output 0 status Does it output @ status 
when sending the hold tone? 
when sending...

Service Check Point-8 
Can not CO call originate (DP). . . . . In case of the A-K communication of TEL is normal 
* In case of call from COLI 
(I ) Does RLI operate by the call data of TEL? 
(no dial tone can be heared) 
t Does RLI operates by 
Does it output Q-J,! 
status? (Q status? 
(2) Does R L3 and 5 operates by call dialing data of TEL ? 
20 
21 
IC4 
22 
23 
1 1 1 
RL3 RL4 RL5 RL6 
Qi3 IC24 I   
0 
I t 
1 
Does R L5 operates during the dialing? 
Does it output 0 status? 
Does R L3 function ON 
and...

Service Check Point-9 
Can not call CO originate (DTMF) . . In case of the A-K communication of TEL is normal 
* In case of call from COLI 
(I) 
(2) 
Does RLI operates by the call data of TEL? 
(no dial tone can be heared) 
t Does R Ll operates by 
Does it output 
@ status? 0 status? 
Does RL5 operates by the call dial data of TEL? 
I 7 I 
(confirmation tone is too louder) 
Does it output 
@ status? 
(3) Does it output the DTMF dial signal? 013 IC24 
h--G - 0  IC24@ 
Does it operates when the 
DTMF dial...

Service Check Point-10 
Can not dial with specified TEL at power failure 
(I 1 Does it supply the battery voltage? 
R4 
2 
ZD 
,,. Battery side with:5  i 
t I 
I R48 
I, 
RL9 
DlO 
ib 
0 
CC52 
Battery 
I-= 
* Ia 
2 
1) Does Qll turn to OFF when the AC power is failed? 
2) Does IC8 (pin No. 2) return to @ status by 011 is OFF? 
3) Does Q9 turn to ON? 
4) Does R L9 operates?  

‘. 
_ . . 
. . . 
ORDER NO. LCD850014 Sl 
Technical Inform&ion 
Easa-Phone;” 
Key Telephone System VA-208 
VA-208 10 
A SUPPLEMENT V 
W INTRODUCTION 
This manual is for the key telephone with built-in speakerphone and optional equipments of the key telephone system VA-208. 
Panasonic. 
Panasonic Company 
Panasonic Hawaii, Inc. 
Division of Matsushita Electric Corporation of America 91.238 Kauh St., Ewa Bearh, Hor~olulu. Hawaii 96808-0774 
One Panasonic Way. Secaucus. New Jersey 07094  

HEXPLANATION OF CIRCUIT OPERATION 
1. Key telephone with built in speakerphone 
1.1 Conversation 
Handset is connected to T and R line when HSI is ON. 
R38 
(I) 
(2) 
R2f3 
DE I 
L 1 Incoming 
Signal R33 
Receiving circuit 
The received voice signal is connected to the receiver via the following path. 
T, R terminal + HSI (ON) + DBI (Rectifier) + Sink circuit (Provided to maintain conversation quality by a 
constant current supply for various distance conditions to the Central Office Exchange) -+ Tl -+...

1.2 Functional operation circuit 
HSI 
Speakerphone Unit 
HS3 1 
+5v 
R42 
;:I RI6 
017 
P60 
P61 
P52 
P62 
P63 
1 P93 
P90 
P53 
P91 
I 
P20 
PB3 
P82 
P81 
1 PBO) R43 
R36 
CN5 
(I) COL lamp flashing during CO line use (eg. COL 1). 
When the COL incoming call lamp signal arrives to the TEL from the KSU, pin (32) of ICI outputs the control 
signal (0.5 sec. @ 
, 0.125 sec. @ 00 and 1.5 sec. @ ). The lamp control signal turns ON the COL lamp 
when the signal becomes 0 and turns OFF the COL lamp when the...

(3) Intercom call tone sounds and intercom voice call. 
When the intercom call sounding signal and voice call signal is sent to the TEL from the KSU, pin (36) of ICI 
becomes @ level. The @ level-signal is sent to pin (5) of IC5 via D4 and turns IC5 to ON. The following opera- 
tion is the same as in clause 2.2. 
(4) Interrupt tone control and interrupt tone output. 
The interrupt tone control signal is sent to the TEL from the KSU, pin (23) of ICI becomes @ level, then the 
receiving SW at busy IC5 (pin...

ORDER NO. LCD850014 Sl 
Fl 
’ Technical Information 
1 Easa-Phone;” 
Key Telephone System VA-208 
A SUPPLEMENT V 
VA-208 IO VA-20820 
H INTRODUCTION 
This manual is for the key telephone with built-in speakerphone and optional equipments of the key telephone system VA-208. 
Panasonic. 
Panasonic Company 
Panasonic Hawaii, Inc. 
Divismn of Matsushita Electric Corporation qf America 91-238 Kauh St,, Ewa Beach, Hor~olulu. Hawaii 96808.0774 
One Panasonic Wav. Secaucus. New Jersey 07094  

CONTENTS 
BLOCKDIAGRAM ............................. . ................................... 1 
1. 
Key telephone with built in speakerphone (VA-20821) ...................................... 1 
2. Doorphone Adaptor (VA-20860) 
..................................................... 2 
3. Extension Card (VA-20840) 
........................................................ 2 
4. Extension Card (VA-20841) 
........................................................ 2 
EXPLANATION OF CIRCUIT OPERATION...