X501 (Base Unit), X201 (Handset) Check; Adjust Battery Low Detector Voltage (Handset) - Panasonic KX-TG5571BXM Service Manual

8.3.

X501 (Base Unit), X201 (Handset) Check

Equipment: Frequency counter
Check Point for measurement: BCK
Checking tolerance: 13.824MHz ± 270Hz (Base Unit)/13.824MHz ± 100Hz (Handset)
8.3.1. Check and Adjust X501 (Base Unit) Frequency
1. Set up Base Unit in TEST mode.
2. Press following keys in order to Adjust Crystal mode. [INTERCOM], [INTERCOM], [INTERCOM], [1], [4]. Check BCK frequency.
3. If the BCK frequency is out of the checking tolerance (± 270Hz), adjust to Adjustment tolelance (± 30Hz) by pressing [ ] or [ ]
key.
Adjustment Tolerance: 13.824MHz ± 30Hz
4. Press [INTERCOM] key to write the new frequency factor in Memory.
5. Turn the power off. Then this value is available.
Cross Reference:
Adjustment Mode (P.46)
8.3.2. Check and Adjust X201 (Handset) Frequency
1. Set DC power supply to 3.9V.
2. Set up Handset in TEST mode (Adjustment flow).
3. Press [1] key to Adjust Crystal mode ("Clock Adj." is displayed on LCD). Check BCK frequency.
4. If the BCK frequency is out of the checking tolerance (± 100Hz), adjust to Adjustment tolelance (± 30Hz) by pressing [ ] or [ ]
key.
Adjustment Tolerance: 13.824MHz ± 30Hz
5. Press [TALK] key to write the new frequency factor in EEPROM.
6. Turn the power off. Then this value is available.
Cross Reference:
Adjustment Mode (P.50)
8.4.

Adjust Battery Low Detector Voltage (Handset)

After Handset´s DSP (IC201) or EEPROM (IC241) replacement, Re-writing Battery Low voltage to EEPROM is required.
With following Handset Adjustment Flow, adjust DC power supply and DC voltmeter by the procedure below.
1. Set DC power supply to 3.9V.
2. Set up Handset in TEST mode (Adjustment flow).
3. Press [1] key and [OFF] key to Adjust Batt Low mode. ("Bat Adj." is displayed on LCD)
4. Change the voltage of the DC power supply to 3.50V accurately. Check the voltage at P.C. board pads because some voltage
drops occur due to the usage of long or thin cables.
5. Press [TALK] key to write voltage value in EEPROM.
6. Turn the power off. Then this value is available.
Note:
Refer to Handset Reference Drawing (P.53) for connection of DC power supply and voltmeter.
Cross Reference:
Adjustment Mode (P.50)
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KX-TG5571BXM / KX-TGA550BXM