Tone Dialing Problems; No Ringing Sound When Ring Signal Is Input - Panasonic KX-TSC62SXB Service Manual

8.4.

Tone Dialing Problems

Can the DTMF sound
be monitored ?
Does the DTMF signal
appear at base of Q401?
Check Q401.
8.5.

No Ringing Sound When Ring Signal is Input

Call the unit from another telephone.
Does a sine wave of approximately 60V
or more appear across Tip and Ring?
Is the voltage across Pin 8 and Pin 2 of
IC1 30 Vp-p?
Does the tone ringer output signal
appear across Pin 5 and Pin 2 of IC1?
Check the Ringer SW201
NO
YES
YES
NO
YES
YES
YES
Does the DTMF signal
appear at Pin56 of IC801?
YES
Check C481~C484,
R481~R483 and Q401
Check C481~C484 and
R481~R483
NO
Check the telephone line.
NO
Check R201 and C201
NO
Check IC1, R202, R203,
C202 and C203
13
KX-TSC62SXB/KX-TSC62SXW
NO
Check IC801 and X2.