Dell 3115cn Service Manual page 69

4. Other Problems
- Branch Connection (Parallel Connection)
During fax reception, if the handset of another telephone on a branch connection is lifted, the
received image may be corrupted or a transmission error may occur. Branch connection may also
interfere with caller identification, call waiting, the receiving operation of connected telephones.
- Call Waiting
If a call comes in during fax transmission/reception, the image may be corrupted.
- DSL (Digital Subscriber Line)
DSL, a high-speed digital transmission method using existing telephone lines, has several types.
These include ADSL (Asymmetric Digital Subscriber Line) with differing upstream and downstream
transmission speeds, SDSL (Symmetric Digital Subscriber Line) with symmetrical upstream and
downstream transmission speeds, and VDSL (Very high bit rate Digital Subscriber Line) which fea-
tures higher speed. However, because the line is used for both voice and data transmission, various
problems may occur, such as noise during spoken conversation, low sound volume, and mis-dialing.
Replacing the splitter may improve the situation.
- Noise
If electronic equipment (television, computer, microwave, etc.) or devices equipped with motors are
located near a fax machine, noise from them may degrade the line condition.
Also, a telephone line, acting as an antenna, may absorb electric waves generated from wireless or
broadcasting equipment.
Because fax data is audio data, the line quality affects the quality/stability of image data as well as
that of conversation.
- Grounding
Improving the grounding may help to increase the communication speed.
If a two-conductor power cable is used for a 115V model, replace the cable with the three-conductor
cable supplied with the product.
Version 1 2006.11.21
Chapter 1 Troubleshooting