Panasonic KX-F910BX, Service Manual

Page: 66 / 237

|
70
|
KX-F910BX
(1) Defective ITS (Integrated telephone system) section
Following the ITS section or NCU section, search for the route between the microphone and
the telephone line (sending) or between the telephone line and the speaker (receiving) where the signal disappears.
Check the components at that point.
Does the voltage at 3 pin of
IC151 change between high
level and low level?
Check the Bell detection
circuit.
Does a DTMF signal appear
at 44 pins of IC11 (digital
board)?
Following the NCU section and ITS section
and search for the point on the route between
44 pins of IC11 and the telephone jack.
Where the signal disappears.
Check the components at that point.
Is the Bell detection circuit
OK?
Does a ring tone
signal appear at 44
pins of IC11 (digital
board)?
Following the ITS section and search
for the point on the route between
the modem and the speaker where
the signal disappears.
Check the components at that point.
Replace IC11.
Replace IC11.
Replace PC102.
Does the voltage at 3 pin of
IC151 change between high
level and low level?
Replace PC102 or R281.
Check IC151.
Check the pulse dial circuit.
1 No speakerphone transmission/reception
2 No pulse dialing
3 No ring tone
4 No tone dialing
YES
NO
NO
NO
NO
YES
YES
YES
YES
NO