Thermal Head Section - Panasonic KX-F680BX Service Manual

KX-F680BX/KX-F2681BX

3-14. THERMAL HEAD SECTION

Is the voltage at pin 8 of CN251.
(Analog Board) 0~1 V? (When copying)
YES
Is the voltage at pins
5,6 of CN301 23~24 V? (Power unit )
YES
Is the amplitude at
pins 1, 4~7 of CN11
4~5 Vp-p?
YES
Is the amplitude at pins
1~3 of CN11 4~5 Vp-p?
YES
Check the cable of CN11
and CN301. (Power unit)
OK
Replace thermal head.
NO
NO
Check switching power
supply section.
(Refer to page 76)
NO
Take out CN11 and check the
amplitude again.
OK
Check the solde at pins
22, 25~28 of IC1 or re-
NO
place IC1. (Digital Board)
Take out CN11 and
check the amplitude
again.
OK
Check the solder at pins
23, 24 of IC1.
Is the voltage at pin 119
of IC1 4~5 V? (Digital
Board)
Check the solder at pin
119 of IC1 or pin 8 of
CN251.
NG
NG
| 88 |
YES
NO
Check the voltage at pin
38 of IC1, 3 V (0 ) V
(65 ) about 2.6V (25 ).
OK
Check IC1.
Check R47, R48, R49,
C37, C38 and C39.
Replace the thermal
head.
NG
2V