Lexmark C750 Service Manual page 164

5060-00x
HCIT inoperative
Before proceeding with this service check make sure the 2000-sheet tray option is properly
connected to AC power.
•
If a finisher is installed:
•
The AC jumper should go from the HCIT to the finisher. The finisher AC power cord should attach to the AC
voltage source. The base printer power cord should plug into the AC output connector on the HCIT.
•
If a finisher is not installed:
The printer power cord plugs into the HCIT AC outlet and the power cord from the HCIT plugs into the AC
voltage source.
Note: Make sure the electrical outlet is working properly and all power cords are plugged in correctly. Make sure
the slide switch on the LVPS is toward the right.
The system board status LED can be observed by removing the rear cover. The LED is mounted on the HCIT
system board.
Step Action and questions
1 Does the printer power up and work normally when
plugged into the AC outlet on the HCIT?
2 Check the system board LED. Is it is on solid or
blinking?
• On solid means that the HCIT has detected the
front door or side door open.
• Blinking means that the system is operating.
Is the LED on solid or blinking?
3 Measure the voltage at TP3 (+5 V dc test point) on the
HCIT system board. The voltage should measure
approximately +5 V dc.
Is the voltage correct?
4 Measure the voltage at CN2 pin 2 on the HCIT system
board. The voltage should measure approximately +5
V dc.
Is the voltage correct?
5 Check the AC line voltage at the input to the LVPS.
Is the voltage correct?
6 Check the AC cable from the HCIT AC inlet to the
LVPS.
Are the cables good?
2-130
Service Manual
Yes No
Go to step 2 Go to step 5
If the LED is on Go to step 3
solid, check the
front and side
doors. If the LED is
blinking, replace
the HCIT system
board
Replace the HCIT Go to step 4
system board
Replace the HCIT Go to step 5
system board
Replace the HCIT Go to step 6
LVPS
Determine where Replace the cables
the AC line voltage
is being lost to the
HCIT. Repair as
necessary.