Gestetner B147 Service Manual page 322

COPY SERVICE MODE
3-921 [Forced Toner Refresh] Forced Toner Refresh
Perform forced toner refresh mode.
When the developer has deteriorated or when prints are made in a very low humidity
condition, dirty background may appear continuously.
When this kind of dirty background appears, check whether or not the development
gamma is within the target (SP3-120 and 121). If the development gamma is not
within the target, do this SP mode.
The machine automatically does the toner refresh mode in the following sequence.
1. Consumes toner in the development unit without toner supply until toner end is
detected
2. Starts toner recovery mode.
3. Starts process control self-check.
NOTE: If toner is drastically consumed for a short time, this may cause carrier to flow
out. To prevent this, toner is consumed over a long period of time. (It takes about 20
minutes to complete this toner refresh mode).
3-921-1 K
3-921-2 All Color
3-922 [OPC Refresh2]
Specifies when the OPC refresh is executed for CMY drums, which forcibly creates a
temporary 15mm-wide toner line on the drum surface by applying the development
bias (200V) and turning on the development clutch at the end of a job.
Note that this OPC refresh is a separate process from the one controlled by SP 3-920
and 3-921.
3-922-1 Mode Set
3-975 [P Control Result] Process Control Self-check Result
Displays the result of the latest process control self-check.
All colors are displayed. The results are displayed in the order "K Y C M"
e.g., 1 1 9 1: The self-check for Cyan failed but the others were successful
See the troubleshooting section for details
3-975-1 P Ctrl Result
B147/B149/B190
*BCU
[ 0 ∼ 2 / 1 / 1 /step ]
0: Disable (OPC refresh is not executed.)
1: Low coverage (OPC refresh is executed
after an output of low coverage ratio.)
2: Every time (OPC refresh is executed after
every job.)
*BCU [ 0 to 9999 / - / 1/step ]
5-34 SM