40
Phaser 780 Color Printer
Print engine troubleshooting
Printer will not power up
When you switch on the printer, the control panel does not light, the fans do not
rotate, the carousel motor does not cycle, and the printer does not go into warm-
up.
1.
110VAC IN Check
a.
Inspect the AC Power Cord. Is the AC Power Cord plugged into the
printer, and is the other end plugged into an AC wall outlet?
b.
Check the voltage at the AC wall outlet. Is there approximately
110 VAC (or 220 VAC if the printer is the 220 VAC model) at the AC
wall outlet?
c.
Remove the rear cover.
d.
Measure the voltage between the two low voltage power supply
solder points located next to the AC power jack. Is there 110 VAC
between the two points?
2.
Low voltage power supply check
a.
Measure the voltage between P33-3 on the low voltage power
supply and frame ground. Is there +5 VDC between P33-3 and
frame ground. If not, replace the low voltage power supply.
a.
Check for +24VDC between P32-3 on the low voltage power supply
and frame ground. Replace the low voltage power supply. Check
for +24VDC between P32-8 and frame ground. If voltage is at pin 3
but not at pin 8, check the front cover, fuser and paper feeder
interlock switches. Is there +24VDC between P32-11 and frame
ground? If not, replace the power supply. Check for a short in the
24 volt components (particularly on the paper feed motor circuit
board).
3.
Low voltage power supply loading check
a.
Disconnect P32 and P33 from the low voltage power supply.
b.
Measure the voltage between P33-3 on the low voltage power
supply and frame ground, and between P32-11 on the low voltage
power supply and frame ground. Is there +5 VDC between P33-3
and frame ground, and is there +24 VDC between P32-11 and frame
ground? If not, replace the low voltage power supply.
4.
Engine control board loading check
a.
Reconnect P32 and P33 to the low voltage power supply.
b.
Refer to “Wiring Diagrams” on page 185 and one by one disconnect
components that are connected to the engine control board.
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 ...