KX-NT551RU-B - Panasonic Telephone Service Manual (repair manual). Page 20

20

This unit has the KEYs and LEDs Test mode.
By using this mode, you can easily check KEYs and LEDs.

• Unit for Test phone
• AC adaptor or Ethernet cable(PoE).

1. Connect power plug(AC adaptor/PoE).
2. Press "1","*"and "CONF" keys at the same time within 5 seconds after power on. Keep it until  "Now Loading" is displayed on

LCD.

3. Release keys.
4.After 10 seconds,all red LED turn on and beep sounds is heard.

1. Then the LCD displays [HOOK Test].

(When skip [HOOK Test], Press SP-PHONE key. )
The SP-PHONE LED is on/off according to HOOK switch.
Press SP-PHONE key.

2. Then the LCD displays [HEADSET Test].

(When skip [HEADSET Test], Press SP-PHONE key. )
The SP-PHONE LED is on/off according to Headset detection.
Press SP-PHONE key three times slowly.

3. Then the LCD displays all dots.

Confirm all dots of LCD and backlight are on.
Press SP-PHONE key.

[KEYs Test]
4.  Then the LCD displays [Key-Check Test] .

Press all keys except SP-PHONE key. 
Press SP-PHONE key. LCD displays [Key-Check OK]

[LEDs Test]
5. Confirm all red LEDs and intercom LED turn on.

Press SP-PHONE key.

6. Confirm all red LEDs of CO line and Ringer change to green

Press SP-PHONE key

7.  Then the LCD displays [RESONANCE Test]

Confirm the resonance by speaker sound.

8.  Then the LCD displays [ACOUSTIC Test]

This TEST mode is not used in service.Press SP-PHONE key four times.Then it returns the first.

It is OK to quit anytime during test mode. Disconnect AC adaptor or Ethernet cable(PoE).