Panasonic KX-NT366RU (serv.man2) Service Manual ▷ View online
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KX-NT366RU/KX-NT366RU-B
4.2.
Circuit Operations
4.2.1.
Main-CPU (IC1)
The DSP , MAC, CODEC and the CPU are built into the VoIP (IC1).
The FLASH (IC2) and the SDRAM (IC3) are connected to the CPU. The contents of the FLASH are expanded to the SDRAM at
start-up. It also stores each setting.
If the LCD is not displayed in the operation but there is no problem on the LCD, then the failure of the CPU system memory (IC2
and IC3) should be considered.
The FLASH (IC2) and the SDRAM (IC3) are connected to the CPU. The contents of the FLASH are expanded to the SDRAM at
start-up. It also stores each setting.
If the LCD is not displayed in the operation but there is no problem on the LCD, then the failure of the CPU system memory (IC2
and IC3) should be considered.
4.2.2.
LCD Circuit
LCD data are outputted from pin 54 of IC4 to LCD module.
IC19 is an inverter for a charge pump circuit which outputs the voltage necessary for LCD driving.
IC19 is an inverter for a charge pump circuit which outputs the voltage necessary for LCD driving.
• 4.5V from -1.2V generated at IC19 as a reference to +3.3V of the power supply voltage is pressurized four times in the LCD mod-
ule and used as LCD driving voltage (approx. 18V).
LCD contrast is set by electronic volume in the LCD module.
The type of the LCD module is distinguished by pin 56 of IC4.
KX-NT366 uses a 24 digits x 6 lines LCD.
The type of the LCD module is distinguished by pin 56 of IC4.
KX-NT366 uses a 24 digits x 6 lines LCD.
The lighting of the backlight is controlled by Q601.
• IC4-pin 52 H
→Q601-ON→Backlight ON
• IC4-pin 52 L
→Q601-OFF→Backlight OFF
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KX-NT366RU/KX-NT366RU-B
4.2.3.
LCD Circuit (Self-labeling)
LCD data are outputted from pin 54 of IC5 to LCD module.
LCD contrast is set by electronic volume in LCD module.
Self-labeling uses a 12 digits x 12 lines LCD.
LCD contrast is set by electronic volume in LCD module.
Self-labeling uses a 12 digits x 12 lines LCD.
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KX-NT366RU/KX-NT366RU-B
4.2.4.
Reset Circuit
Reset Signal is outputted from IC12 and inputted into IC1 and IC2.
4.2.5.
Ethernet Circuit
The Ethernet hub IC (IC6, IC7) is used for the Ethernet interface.
It is connected from IC6 to the Ethernet port (JK2) through a transformer and so is isolated.
Also, LAN port (JK2) gets power from the Ethernet line for PoE (Power over Ethernet) as shown below.
It is connected between IC7 and the VoIP (IC1) by high-speed bus called MII (Media Independent Interface) bus operating with
25MHz.
It is connected from IC6 to the Ethernet port (JK2) through a transformer and so is isolated.
Also, LAN port (JK2) gets power from the Ethernet line for PoE (Power over Ethernet) as shown below.
It is connected between IC7 and the VoIP (IC1) by high-speed bus called MII (Media Independent Interface) bus operating with
25MHz.
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KX-NT366RU/KX-NT366RU-B
4.2.6.
Analog Circuit
This circuit performs the setting of the call path/vol. adjustment in each call mode by a built-in DSP of VoIP(IC1).The audio gain
of each call is determined by download data from PBX or by internal data from flash memory(IC2).
In case of the extension call between NT300, The telephone call becomes a characteristic in accordance with G722.
of each call is determined by download data from PBX or by internal data from flash memory(IC2).
In case of the extension call between NT300, The telephone call becomes a characteristic in accordance with G722.
1. Handset Call
Transmitting signal is inputted from handset microphone, and amplified by IC24 and IC25
→
Inputted to IC1-pin112
→ A/D conversion and Gain adjustment by a built-in DSP of IC1 → then sent to PBX.
Transmitting signal inputted from handset microphone is controlled by transmission switching SW IC27 as follows;
IC27-pin11 L: Handset Call
(IC27-pin11 H: Headset Call)
Transmitting signal inputted from PBX
IC27-pin11 L: Handset Call
(IC27-pin11 H: Headset Call)
Transmitting signal inputted from PBX
→Gain adjustment by a built-in DSP.
Receiving signal inputted from PBX
→ Gain adjustment by a built-in DSP of IC1 → D/A conversionand outputted from IC1-
pin115.
→ Amplified by IC20, and outputted to handset.
2. Headset Call
Transmitting signal is inputted from headset microphone, and amplified by IC24 and IC25
→ Inputted to IC1-pin112 → A/D
conversion and Gain adjustment by a built-in DSP of IC1
→ then sent to PBX.
Transmitting signal inputted from headset microphone is controlled by transmission switching SW IC27 as follows;
IC27-pin11 H: Headset Call
(IC27-pin11 L: Handset Call)
IC27-pin11 H: Headset Call
(IC27-pin11 L: Handset Call)
Receiving signal inputted from PBX
→ Gain adjustment by a built-in DSP of IC1 → D/A conversion and outputted from IC1-
pin115.
→ Amplified by IC20, and outputted to headset.
3. Speakerphone Call
Speakerphone call realize all double-call by a built-in DSP(echo-canceller)of IC1. For a call In the most appropriate condition,
DSP checks voice level of the calling party, acoustics in a room, voice level of the other party and state of the line of contact,
and cancels echo in transmitting and receiving at the start of calling. It operates in a half double-call state in a few seconds for
the check.
DSP checks voice level of the calling party, acoustics in a room, voice level of the other party and state of the line of contact,
and cancels echo in transmitting and receiving at the start of calling. It operates in a half double-call state in a few seconds for
the check.
Transmitting signal is inputted from microphone and amplified by IC23
→inputted to IC1-pin113 → A/D conversion and Gain
adjustment by a built-in DSP of IC1, then sent to PBX through echo canceller.
Receiving signal inputted from PBX
→ Gain adjustment by DSP through a built-in echo canceller of IC1 → D/A conversion
and outputted from IC1-pin116
→ Amplified by IC21 and outputted to Speaker.
Power Amp IC21 is controlled as follows;
IC21-pin1 L: ON
IC21-pin1 H: OFF
IC21-pin1 L: ON
IC21-pin1 H: OFF
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