Oki OKIOFFICE84 Maintenance Manual page 466

10: No sound from
the speaker
Monitor or buzzer
buzzer
Pulse wave input is provided
at pin 5 of IC11 when the
key is pressed or the soft
ringer goes
No
Replace IC2.
Monitor
Communication normal
No
See sending or receiving NG.
Yes
Replace IC11.
H - 11
Yes
No
Replace TR513.
Either pin 9, 10, or 11 of IC11
No
becomes 5V when the key is
pressed or the soft ringer goes
or during communication
Yes
Sine wave or modulated wave
No
is input to pin 3 of IC5 when the
key is pressed or the soft ringer
goes or during communication
Yes
Sine wave or modulated wave is
output from pin 5 of IC5 when the
key is pressed or the soft ringer
goes or during communication
Yes
Check CN9.
Sine wave or modulated
wave input is provided at
pin 13 of IC11 during
communication
Yes
No
Replace IC5.
40672201TH Rev. 4