No Dial Tone; Defective Mf Dial - Dell 1600n - Multifunction Laser Printer B/W Service Manual

7.4 Fax & Phone Problems

7.4.1 No Dial Tone

• Description While on-hook button is pressed, there is no dial tone.
Check and Cause
1. Check if the telephone line cord is connected to
TEL LINE correctly.
2. Check if it makes CLICK sound while OHD key is
pressed.
3. Check the connection of HARNESS between the
LIU and the Main B'd.
4. Check if the SPEAKER is connected correctly.

7.4.2 Defective MF DIAL

• Description The MF DIAL is not functioning.
Check and Cause
1. Check if the telephone line is connected correctly.
2. Wile the BUTTON KEY is pressed, check to catch
a CLICK sound.
3. Check the connection of HARNESS between the
LIU and the Main PBA.
Solution
1. If the telephone cord is normal but there is no dial tone,
then try to replace the LIU B'd.
2. If you cannot hear the OHD CLICK sound, the OPE
Ass'y may be defective. Try to replace the OPE Ass'y.
3. Check the Speaker connection, and try to replace it.
4. Lastly, try to replace the Main B'd.
Solution
1. If you cannot catch the OHD CLICK sound, the OPE
Ass'y may be defective. Try to replace the OPE Ass'y.
2. If you can catch a CLICK sound, after checking the
connection of HARNESS between the LIU and the
Main PBA, try to replace the HARNESS.
3. The problem still persists, then replace the LIU and the
main B'd in sequence.
Notes:
Product supports the MF DIAL type only.
Troubleshooting
Service Manual
7-17