Panasonic KX-TC1872B Service Manual page 29

8.9. Check the RF Unit
8.9.1. Finding out the Defective Unit
Prepare HS JIG (Handset-jig) and BS JIG (Base Unit-jig). Place
the HS JIG on the cradle of the base unit for checking, then
confirm that they are linked. Place the handset for checking on
the cradle of the BS JIG, then confirm that they are linked. How
to confirm the link is as follows; press the TALK button and
confirm that the LEDs of the base unit is turned ON.
8.9.2. Check Items
8.9.2.1. Handset-jig (HS JIG) for Base
Unit
The handset unit jig also uses two modes: TEST SUPER LOW
mode and NORMAL POWER mode. These modes alternate
when the handset CLEAR button is pressed:
(1) NORMAL POWER mode (Stand-By). In this mode the LCD
will remain blank.
(2) TEST SUPER LOW mode. When the CLEAR button is
pressed, the LCD will show TEST SUPER LOW. This test
simulates the handset is at very large distance from the base
unit and the TX signal from handset to base is very small.
Procedure: First place handset jig on base under test to
charge (exchange security code); press CLEAR and then TALK
to operate. The LCD will show TALK and TEST. This means
that the base unit sensitivity is OK.
* In TALK mode, LCD display change to "TALK TEST" or
"TALK" on [TEST POWER] mode or [NORMAL POWER]
mode.
* HS JIG becomes [NORMAL POWER] mode immediately after
the power supply turning on.
NOTES:
1) If when setting the handset to TEST SUPER LOW mode,
if handset beeps 3 times and the LCD shows "No link to
base. Place on cradle and try again", press 2, 5, 8, 0
simultaneously and then disconnect battery. Re-install
battery, place unit on cradle to get security codes and tries
again.
2) Only KX-TC1851B with marks HS JIG can be used for
troubleshooting. Regular KX-TC1851B production samples
does not have the software needed for troubleshooting.
3) You can differentiate the jig from a regular unit because
the jig has silver bottom cabinet (base) and back cabinet
(handset).
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KX-TC1868B / KX-TC1871B / KX-TC1872B