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Flow Chart of Troubleshooting and Circuit Diagrams
3-16
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3-1-6. Speaker Part
No signal
at the Pin#2, 4 of U302
NO
Check the U302
YES
Is there signal
at the R341 of U301
No signal
at the C345 of U301
Is the Terminal of
Speaker OK?
Check
SpeakerTerminal
YES
NO
NO
YES
END
NO
YES
Check the UCP100
The type of sound from speaker
is Melody or Key Tone
YES
Speaker Phone Mode of Voice?
YES
NO
NO
Check the Receiver Part
Check the U301
The type of sound from speaker
is Key Tone (from YMU)
Check the R336, C351 or
UCP100
NO
The pin #7 of U300 = 2.8V and
The pin #32 of U300 = 2.6V?
YES
NO
Check the U300
The pin #29 of U300 is High?
NO
Check the UCP100
There is No sound
from Receiver
No signal
at the Pin#2, 4 of U302
NO
Check the U302
YES
Is there signal
at the R341 of U301
No signal
at the C345 of U301
Check
SpeakerTerminal
YES
NO
NO
YES
END
NO
YES
Check the UCP100
The type of sound from speaker
is Melody or Key Tone
YES
Speaker Phone Mode of Voice?
YES
NO
NO
Check the Receiver Part
Check the U301
The type of sound from speaker
is Key Tone (from YMU)
Check the R336, C351 or
UCP100
NO
The pin #7 of U300 = 2.8V and
The pin #32 of U300 = 2.6V?
YES
NO
Check the U300
The pin #29 of U300 is High?
NO
Check the UCP100