Ricoh A172 Service Manual page 470

Tech Service Bulletin No. A172/A199 – 008
Page 2 of 3
3. Troubleshooting procedure for insufficient ID max (or excessive ID max)
As the new Type "J" toner replaces the old Type "F" toner in the developer, the history of the Vcnt Correction
for the old toner remains, therefore the toner density correction may be slightly excessive and result in toner
density slightly less than that originally with the old toner. (The opposite may occur if the toner is switched
from new type to old type.)
In most cases, a change in image density can be corrected by performing ACC or Printer Calibration,
however it may cause a service call depending on the customer.
If insufficient ID max (or excessive ID max) is encountered and the cause is identified as the switching of
toner from old type to new type (or from new type to old type) perform the procedure outlined below:
Insufficient ID max
1. Check the following items.
1.1. The image density remains light, even if the ACC or Calibration is performed.
1.2. Process Control Self-check is set (SP Special Feature page1 Auto Process Control Self-check set
to PID), and has been successful. If the Self-check has not been successful, find and correct the
cause.
1.3. Vt (TD Sensor Output) does not vary greatly from the Vref (judgement standard |Vt -Vref| ≤ 0.2V) If
Vt varies greatly from Vref, make copies of the C4 test chart until Vt falls within an acceptable
standard.
1.4. TC Correction Threshold (SP Special Feature page1) is reset.
1.5. The density of the ACC Pattern 10
1.6. Even if the IDmax and the Shadow setting in the printer gamma Correction are adjusted, the image
density remains light.
2. If the Vcnt Correction is on (SP Adjustment page 16 No. 1: 00001), switch it "Off" (00000).
3. Change the Vref for the colors with low density from the current Vref - 0.35V. (See Note *1)
(On SP Adjustment page 12, input Vref - 0.35 for the Toner Sensor Control Target.)
4. After inputting the value, confirm that the setting has been changed by looking at the SP Data Output for
page 1 on the display. (See Note *2)
5. After the adjustment, watch the Vt on the SP Data Output page1 display and make copies of the C-4 test
chart (A3/FC mode, approx. 10 copies) until the Vt stabilizes at |Vref - Vt| ≤ 0.2V. (See Note *3)
6. If the ID max is still insufficient, set SP Adjustments page 4, Toner Max M/A target(s) to 1.3.
7. If necessary, perform the ACC and the Printer Gamma Adjustment.
Excessive ID max
1. Check the following items.
1.1. Even if the ACC or Calibration is done, the image density remains dark.
1.2. Process Control Self-check is set, and has been successful. If the Self-check has not been
successful, find and correct the cause.
1.3. The TD Sensor Output Vt does not vary greatly from the Vref. (Standard |Vt -Vref| ≤ 0.2V) If Vt
varies greatly from Vref, make copies of C4 test chart until Vt falls within an acceptable standard.
1.4. The density of the ACC Pattern 10
1.5. Even if the IDmax and the Shadow setting in the printer gamma Correction are adjusted, the image
density remains dark.
2. Change the Vref for the colors with high density from the current Vref + 0.35V. (On SP Adjustment P. 12,
input Vref + 0.35V for the Toner Sensor Control Target.) (See Note *1)
3. After inputting the value, confirm that the setting has changed by looking at the SP Data Output Page 1
on the display. (See Note *2)
4. For the affected colors, make five A3 sky shot copies (ten copies for A4). (See Note *3)
5. After the adjustment, watch the Vt on the SP Data Output P.1 display and make copies of the C-4 chart
(A3/FC mode, approx. 10 copies) until the Vt stabilizes at |Vref - Vt|≤0.2V.
6. Wait 5 minutes, then perform the process control Self-check.
7. If necessary, perform the ACC and the Printer Gamma Adjustment.
th
level is equally as low. (There is no need to run the ACC.)
th
level is equally as dark. (There is no need to run the ACC.)
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