Sanyo CLT-99 Service Manual page 15

TROUBLE SHOOTING
h. The ringer does not ring.
Base Station
1. Are the Handset and Base station linked?
YES
2. Does the ringer signal reach pin(1) and (2) of IC901?
YES
3. Is the High/Low signal being emitted to pin (3) and (4)
of IC901?
YES
4. Is the High/Low signal being emitted to pin (28) of IC401?
YES
5. Is the ring TONE signal being emitted to pin (39)
of IC401?
YES
6. Is the ring TONE signal being emitted to pin (8)
and (5) of IC703?
YES
7. Check speaker, CN703.
Handset
1. Is the ringer tone signal being output from pin (43) of IC001?
YES
2. Is the ringer tone signal being reached to (B) of Q699?
YES
3. Check BZ699.
i. The speaker phone does not operate.
1. Are voice communications with the handset possible?
YES
2. Is the level of pin (22) of IC401 "High"?
YES
(i-1) (i-2)
i-1. Receiving signal (Voice signal)
1. Does the receiving signal reach pin (3) IC701?
YES
2. Does the receiving signal reach pin (14) IC706?
YES
3. Does the receiving signal reach pin (8) and (5) IC703?
YES
4. Check the speaker and speaker connector.
CLT-99/SS (S/M) 6 15
NO
Check refer to the section (c) and (d).
NO
Check CN901, L901, L902, D901, D902 and NL901.
NO
Check IC901.
NO
Check Q902.
NO
Is the S401 (RINGER) set to the "ON" position?
YES
Check IC401.
NO
Is the level of pin (1) of IC703 "Low"?
YES NO
Check IC703. Check IC401.
NO
Check IC001.
NO
Check Q699 and D699.
NO
Refer to the station (e) and (i-1).
(e) Transmission signal. (i-1) Receiving signal.
NO
Check IC401.
NO NO
Is the level of pin (22) of Check IC401.
IC401 "High"?
YES
NO
Check IC706 & Q704. Check IC701.
NO
Is the level of pin (1) of IC703 "Low"?
YES
Check IC703. Check IC401.
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TROUBLE SHOOTING
i-2. Transmission signal
1. Is the transmission signal being input to both ends
of the microphone?
YES
2. Does the transmission signal reach pin (23) IC706?
YES
3. Does the transmission signal reach pin (1) IC701?
YES
4. Does the transmission signal reach pin (C) Q701?
YES
5. Refer to the station (e).
(e) Transmission signal.
j. The intercom does not operate.
1. Does the speaker phone operate?
YES
2. Is the level of pin (23) of IC401 "High" ?
YES
3. Does the voice communication of handset?
YES
Receiving signal (Voice signal)
YES
1. Is the signal from the handset being output to pin (18) in IC301?
YES
2. Does the voice signal reach pin (C) Q704?
YES
3. Does the voice signal reach pin (8) and (5) IC703?
YES
4. Does the voice signal reach terminal of speaker?
Transmission signal
YES
1. Does the microphone signal reach pin (23) IC706?
YES
2. Does the transmission signal reach pin (45) IC301?
NO
12/1/00, 3:18 PM
NO
Check MIC and D701.
NO
Check IC706.
NO NO
Is the level of pin (22) of Check IC401.
IC401 "High"?
YES
NO
Check Q701,Q702. Check IC701.
NO
Refer to the section on the speaker phone signal (i).
NO
Check IC401.
NO
Refer to the station (e) and (f).
NO
Check IC301.
NO
Check Q704, Q710.
NO
Is the level of pin 1 of IC703 "Low"?
YES
Check IC703. Check IC401.
NO
Check speaker and speaker connector.
NO
Check IC706.
NO
Check IC701, IC301.
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NO