Image Is Too Light (Image Rendering Problem) - Kyocera TASKalfa 1800 Service Manual

(3) Image is too light.
Print example
Defective part
Paper
1
Drum unit
2
Developer unit
3
Toner container
4
High voltage PWB
5
1. Variance in environments (dew formation).
2. Toner is under supplied, or deteriorated in quality.(Under charged)
3. The volatage of the developing bias is too low.
4. The volatage of the transfer current is too low.
5. The power of LSU laser is too low.
6. The surface potential of the drum is too high.
7. The contact pressure at the trasnfer roller and the drum is too low.
Check description
Check that the paper has mois-
ture absorbed. Check that the
paper has stored in a humid
place.
Check that the drum has dew
condensation.
1. Check if the discharging
lamp is dirty.
2. Check whether it is lit.
Executing U089 to generate PGs
and check the following :
(see page 1-3-41)
1. Check if the device executed
a low-density printing for a
prolonged period.
2. Check if the connecting ter-
minals for developer bias are
deformed.
Shake the toner container up
and down approx. 10 times, and
check the following:
1. Check remaining toner by
the indicator.
2. Check whether the toner
supply inlet is open.
Check the value of the U100.
Check the value of the U140.
Cause of trouble
1. If the paper is damp, replace.Choose a dry
place to store paper.
2. If necessary, install a cassette heater.
(see page 1-2-19)
If a dew condensation is observed, perform
drum refreshing.
(System Menu >Adjustment / Maintenance)
1. If the discharging lamp is dirty, clean.
2. If not cured, or it does not light, replace the
drum unit.
If the device was executing a low-density print-
ing for a prolonged period, perform developing
refreshing.
(System Menu >Adjustment / Maintenance)
If the connecting terminals are deformed,
correct for a proper conduction.
If the message prompting toner replenishing is
shown, the toner inlet is not open, replace the
toner container.
1. If the value obtained by U100 or U140 does
not conform to the default value, reset it to
the default. (see page 1-3-44, 1-3-51)
2. Replace the high voltage PWB.
1-4-70
2NC/2NF/2NG/2NN/3P7/3P8/3P9
Corrective Action