Lexmark C750 Service Manual - Page 146

Lexmark C750 Manual

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5060-00x AC and DC power service check Before proceeding with this service check remove or disconnect any options that may be installed. Turn the machine on. If it operates correctly, reattach one option at a time until the failing option is located. Note: Before proceeding with this service check turn the printer on and check to see if the Power on LED on the engine board is turned on. Step 1 Actions and questions Is the Power on LED on the engine board turned on? Yes Go to "AC power service check" on page 2-112. No Go to "DC power service check" on page 2-113. AC power service check The printer appears to be inoperative when turned on with the Power on/Status LED off, the LCD display is blank, the Fuser lamps do not come on and no motors turn. Step 1 Actions and questions Main AC power-make sure the printer is receiving main AC power. Is the printer receiving AC power? 2 AC power check (wall outlet)-check the AC line voltage at the AC outlet. Is the AC line voltage correct? 3 AC power cord. Is the power cord in good condition? 4 AC Power-Is the power cord plugged into an approved AC outlet. It should not be plugged into a power strip or interruptible power supply. Is the power cord plugged into a correct AC outlet? Go to step 5 Go to step 4 Go to step 3 Yes Go to step 2 No Inform the customer that AC power to the printer is incorrect. Inform the customer that the AC line voltage is incorrect If the cord is in poor condition, replace the cord Plug the power cord into the correct AC outlet. If an outlet is not available, inform the customer. Replace the line cord 5 AC power check (AC line cord)-check the AC line voltage at the end of the AC line cord. Is the AC line voltage correct? Go to step 6 6 Low voltage power supply-turn the power off and disconnect the LVPS from the RIP and engine boards. Check for +5 V dc on the LVPS cables. engine board +5 V dc: J9-2 and J9-3. RIP board +5 V dc: J23-13, J23-14, and J23-15. Is there approximately +5 V dc on all of these connector pins? Go to "DC power service check" on page 2-113. Replace the LVPS. See "Low voltage power supply (LVPS) removal" on page 4-38. 2-112 Service Manual

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2-112
Service Manual
5060-00
x
AC and DC power service check
Before proceeding with this service check remove or disconnect any options that may be installed. Turn the
machine on. If it operates correctly, reattach one option at a time until the failing option is located.
Note:
Before proceeding with this service check turn the printer on and check to see if the Power on LED on the
engine board is turned on.
AC power service check
The printer appears to be inoperative when turned on with the Power on/Status LED off, the LCD
display is blank, the Fuser lamps do not come on and no motors turn.
Step
Actions and questions
Yes
No
1
Is the Power on LED on the engine board turned on?
Go to
“AC power
service check” on
page 2-112
.
Go to
“DC power
service check” on
page 2-113
.
Step
Actions and questions
Yes
No
1
Main AC power—make sure the printer is receiving
main AC power.
Is the printer receiving AC power?
Go to step 2
Inform the
customer that AC
power to the printer
is incorrect.
2
AC power check (wall outlet)—check the AC line
voltage at the AC outlet.
Is the AC line voltage correct?
Go to step 3
Inform the
customer that the
AC line voltage is
incorrect
3
AC power cord.
Is the power cord in good condition?
Go to step 4
If the cord is in
poor condition,
replace the cord
4
AC Power—Is the power cord plugged into an
approved AC outlet. It should not be plugged into a
power strip or interruptible power supply.
Is the power cord plugged into a correct AC outlet?
Go to step 5
Plug the power
cord into the
correct AC outlet. If
an outlet is not
available, inform
the customer.
5
AC power check (AC line cord)—check the AC line
voltage at the end of the AC line cord.
Is the AC line voltage correct?
Go to step 6
Replace the line
cord
6
Low voltage power supply—turn the power off and
disconnect the LVPS from the RIP and engine boards.
Check for +5 V dc on the LVPS cables. engine board
+5 V dc: J9-2 and J9-3. RIP board +5 V dc: J23-13,
J23-14, and J23-15.
Is there approximately +5 V dc on all of these
connector pins?
Go to
“DC power
service check” on
page 2-113
.
Replace the LVPS.
See
“Low voltage
power supply
(LVPS) removal”
on page 4-38
.