Dell 3115CN, Service Manual

Page: 730 / 823

6 – 17
Chapter 6 Principle of Operation (Fax)
Version 1 2006.11.21
7. Fault Isolation Procedure for FAX
Because a FAX is composed of multiple blocks, pinpointing a fault is problematic.
This section describes a simple fault isolation procedure that is based on the contents of 4. FAX
System (Overview).
7.1 Fault Occurs
First, try using the copy function. If the copy function's printing results are correct, the probability of a
fault in the FAX itself is low. The fault is likely in the telephone line or receiving FAX. If the fault is in the
telephone line, first retry sending. If there is no improvement, contact the telephone company. If the
copy function's printing results are incorrect, it can be determined if the fault is in the scanner or printer
by operating each unit separately via a computer.
7.2 Send Fault
1) Problem with printing quality at receiving FAX, such as corrupt image, lines in image, top/bottom
cut off.
a) If copy function is normal
Cause: Degraded telephone line connection caused by noise, etc.; or a fault in receiving FAX's
printer.
Corrective Action:
Determine whether fault is in telephone line or at receiving FAX by trying copy function at
receiving FAX.
If the telephone line condition is degraded, white horizontal lines, missing rows,
and/or cut-off top/bottom may occur.
Branch connections or incoming call (call waiting) may also cause image
corruption.
b) If copy function is faulty
Cause: Dirt or fault in scanner.
Corrective Action:
Clean platen glass or repair scanner. If the original is being sent from the ADF, try executing
a copy with the original placed on the platen glass. If this solves the problem, the fault is in
the ADF.