Gestetner B147 Service Manual page 266

TROUBLESHOOTING GUIDE
Subject
Image density change Image density is too low or
(2) high.
Dirty background Dirty background may
continuously appear on the
left side (relative to paper
feed) under very low
temperature and humidity
conditions.
SM
Symptom
If the machine has never been turned off
and Energy Saver 2 (Auto Off mode) is
disabled, the machine has never
performed the initial process control self-
check, causing the image density to
become low or high.
When the developer has deteriorated or
when prints are made in a very low
humidity condition, dirty background may
appear continuously.
Cause
Change the settings of the following SP modes:
SP3-906-003 Non-use Time 1
0 (Default) to 500
SP3-906-004 Non-use Time 2
30 (Default) to 480
• If Energy Saver 1 is activated (Default: Off), the
non-use time process control self-check will not
function. Therefore, make sure that Energy
Saver 1 is Off (SP5-101-3 or UP mode).
• With the above setting, the self-check
automatically starts after 500 prints and after no
prints have been made for 480 minutes (8
hours). Based on the average daily printing
volume of 500 prints, self-check would be
performed first thing every morning. These
settings are suitable for machines, which are
used during the day and then kept On in Ready
status throughout the night. Therefore, this SP
mode should be set based on the particular way
the customer uses the printer.
Perform forced toner refresh mode (SP3-921-001
or 002).
The machine automatically does this in the
following sequence. (It takes about 20 minutes to
complete this mode.)
4. Consumes toner in the development unit
without toner supply until toner end is detected.
5. Starts toner recovery mode.
6. Starts process control self-check.
NOTE: It takes about 20 minutes to complete this
mode, to prevent carrier flowing out.
4-64
Action
B147/B149/B190