Read Panasonic KX-AT7730RU Service Manual online
18
KX-AT7730 Series
7.2.
HANDSET TROUBLE
Input a signal from the handset.
Yes
Lift the handset.
Does a dial tone sound from the
speaker?
speaker?
Yes
Does a dial tone sound from the
handset?
handset?
Yes
OK
Yes
Is it possible to send a signal
from the handset?
from the handset?
Does the dial tone reach at
emitter of Q8?
emitter of Q8?
Yes
No
Does the dial tone reach at
base of Q8?
base of Q8?
Check the handset, handset cord,
and C31, CN7, CN8, JK2 and
JK3.
and C31, CN7, CN8, JK2 and
JK3.
Yes
Check Q21, Q22, C32, R34,
C27, R208 and Q10.
C27, R208 and Q10.
No
No
No
Check Q5, R23, R21 and C21.
Does a signal reach at base of
Q5?
Q5?
Yes
Check C24, R26, C34, R27, R28.
handset JK2, JK3, CN7 and CN8.
handset JK2, JK3, CN7 and CN8.
No
No
Check Q8.
Does the dial tone reach at
base of Pin7 of IC10?
base of Pin7 of IC10?
Check C26, R32 and IC10
Click on the first or last page to see other KX-AT7730RU service manuals if exist.