Tone (Tel/Fax) Send Test - Oki OKIOFFICE44 Service Manual

7.1.15 Tone (TEL/FAX) Send Test

Start
Connect oscilloscope probe
across the line terminals
L1 and L2.
Perform TONE (TEL/FAX)
SEND TEST. (See 6.12.)
Pseudo-Ring Back Tone
signal appears
across L1 and L2?
Yes
End
Return to section 7.1.1
Troubleshooting
Notes:
The pseudo-ring back tone is sent to the
telephone line for TEL/FAX automatic
switching.
Test Points for the MF signal are difficult to reach.
Use great care to prevent causing a short.
No
MF signal appears across CN10-A8, B8
(S) and CN10-A12, B12 (0V) of R44 board?
Yes
Replace WN5 Board.
Yes
Solved?
No
Replace R44 Board.
7 - 23
No
Replace R44 Board.
Signal route:
IC8-26 to 33 (ADO to AD7)
IC12-7 (S)
Signal route:
CN3-15, 16 T1-3, 1
CN1-3, 4
Possible cause:
CML signal
Service Manual, P/N 59276801
IC8-
OKIOFFICE 44