20
Phaser 780 Color Printer
Image
Density Error
(Error 12)
The image density readings indicate a
problem. The engine control board
detected that the printer image density
was unusually high and attempts to
lower the density have failed.
1.
Power cycle the printer
2.
Ensure the toner cartridges
are fully functional and
relatively full of toner.
3.
Test the toner dispense
motor.
4.
Check the auto-density
calibration sensor for
contamination from toner.
Replace the sensor, if
necessary.
5.
Inspect and reseat the
auto-density calibration
sensor. Ensure the senor’s
solenoid-activated cleaning
blade is in place and moves
freely.
6.
Test the auto-density
calibration sensor. If bad,
replace the auto-density
calibration sensor
7.
Replace the engine control
board
8.
Inspect the four developer
housings. Each magnet
roller should be evenly
coated with toner. Replace a
suspect developer assembly.
9.
Replace the imaging unit
10.
Replace the high voltage
board
Error code
and
message
Description
Corrective action
Summary of Contents for Phaser 780 Color
Page 6: ......
Page 32: ...18 Phaser 780 Color Printer ...
Page 90: ...76 Phaser 780 Color Printer ...
Page 94: ...80 Phaser 780 Color Printer ...
Page 117: ...Service Guide 103 Removing the developer tie plate 780 5 82 Wire clamp Developer tie plate ...
Page 125: ...Service Guide 111 Removing the laser unit Laser unit Laser cover 780 5 47 ...
Page 150: ...136 Phaser 780 Color Printer ...
Page 156: ...142 Phaser 780 Color Printer Multi purpose tray cover FRUs 780 5 121 3 1 4 2 5 ...
Page 158: ...144 Phaser 780 Color Printer Multi purpose tray FRUs 1 4 2 3 7 6 5 8 9 780 5 122 11 12 13 10 ...
Page 160: ...146 Phaser 780 Color Printer Paper feeder cover FRUs 780 5 123 1 2 3 ...
Page 162: ...148 Phaser 780 Color Printer Paper feeder FRUs 1 2 3 5 4a 4b 6 7 780 5 124 ...
Page 164: ...150 Phaser 780 Color Printer Imaging FRUs 1 2 3 4 5 6 7 780 5 125 ...
Page 166: ...152 Phaser 780 Color Printer Developer FRUs 780 5 126 1 1 1 2 2 2 3 3 3 4 4 4 ...
Page 168: ...154 Phaser 780 Color Printer Carousel FRUs 4c 4d 5 4b 4a 3 2 1 780 5 127 6 ...
Page 172: ...158 Phaser 780 Color Printer Fuser assembly FRUs 1 2 3 780 5 129 4 ...
Page 174: ...160 Phaser 780 Color Printer Paper exit FRUs 780 5 130 1 2 3 3 3 3 3 ...
Page 178: ...164 Phaser 780 Color Printer Drive FRUs 780 5 132 1 2 3 4 6 5 9 8 7a 7d 7c 7c 7b ...
Page 182: ...168 Phaser 780 Color Printer Electronics front FRUs 780 5 134 2 4 5 6 3 8 9 7 1 10 ...
Page 184: ...170 Phaser 780 Color Printer Image processor FRUs 780 5 135 1 2 3 6 5 4 7 8 9 12 10 11 ...
Page 198: ...184 Phaser 780 Color Printer ...
Page 233: ...Service Guide 21 ...
Page 234: ...220 Phaser 780 Color Printer ...