HP Color LaserJet Enterprise CM4540 Service Manual - Page 422

Power subsystem, Power-on checks, Power-on troubleshooting overview

Page 422 highlights

Power subsystem Power-on checks The basic product functions should start up when the product is plugged into an electrical outlet and the power switch is pushed to the on position. If the product does not start, use the information in this section to isolate and solve the problem. Power-on troubleshooting overview Turn on the product power. If the control panel display remains blank, random patterns display, or asterisks remain on the control panel display, perform power-on checks to find the cause of the problem. During normal operation, the main cooling fan begins to spin briefly after the product power is turned on. Place your hand over the holes in the left-side cover, near the formatter. If the fan is operating, you will feel air passing out of the product. You can also lean close to the product and hear the fans operating. After the fans are operating, the engine initializes (unless the right or front cover is open, a jam condition is sensed, or the paper-path sensors are damaged). You should be able to visually and audibly determine if the engine has initialized. If the fans turn on and the engine initializes correctly, the next troubleshooting step is to isolate print engine, formatter, and control panel problems. Perform an engine test (see Engine-test button on page 376). If the formatter is damaged, it might interfere with the engine test. If the engine-test page does not print, try removing the formatter and then performing the engine test again. If the engine test is then successful, the problem is almost certainly with the formatter, the control panel, or the cable that connects them. If the control panel is blank when you turn on the product, check the following items. 1. Make sure that the product is plugged directly into an active electrical outlet (not a power strip) that delivers the correct voltage. 2. Make sure that the power switch is in the on position. 3. Make sure that the fan runs briefly, which indicates that the power supply is operational. 4. Make sure that the control panel USB cable is connected. 5. Make sure that the formatter is seated and operating correctly. Turn off the product and remove the formatter. Reinstall the formatter, and then verify that the heartbeat LED is flashing. 6. Remove any HP Jetdirect or other EIO cards, and then try to turn the product on again. NOTE: If the control panel display is blank, but the main cooling fan runs briefly after the product power is turned on, try printing an engine-test page to determine whether the problem is with the control-panel display, formatter, or other product components. See Engine-test button on page 376. 370 Chapter 3 Solve problems ENWW

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Power subsystem
Power-on checks
The basic product functions should start up when the product is plugged into an electrical outlet and the
power switch is pushed to the
on
position. If the product does not start, use the information in this
section to isolate and solve the problem.
Power-on troubleshooting overview
Turn on the product power. If the control panel display remains blank, random patterns display, or
asterisks remain on the control panel display, perform power-on checks to find the cause of the
problem.
During normal operation, the main cooling fan begins to spin briefly after the product power is turned
on. Place your hand over the holes in the left-side cover, near the formatter. If the fan is operating, you
will feel air passing out of the product. You can also lean close to the product and hear the fans
operating.
After the fans are operating, the engine initializes (unless the right or front cover is open, a jam
condition is sensed, or the paper-path sensors are damaged). You should be able to visually and
audibly determine if the engine has initialized.
If the fans turn on and the engine initializes correctly, the next troubleshooting step is to isolate print
engine, formatter, and control panel problems. Perform an engine test (see
Engine-test button
on page
376
). If the formatter is damaged, it might interfere with the engine test. If the engine-test
page does not print, try removing the formatter and then performing the engine test again. If the engine
test is then successful, the problem is almost certainly with the formatter, the control panel, or the cable
that connects them.
If the control panel is blank when you turn on the product, check the following items.
1.
Make sure that the product is plugged directly into an active electrical outlet (not a power strip)
that delivers the correct voltage.
2.
Make sure that the power switch is in the
on
position.
3.
Make sure that the fan runs briefly, which indicates that the power supply is operational.
4.
Make sure that the control panel USB cable is connected.
5.
Make sure that the formatter is seated and operating correctly. Turn off the product and remove
the formatter. Reinstall the formatter, and then verify that the heartbeat LED is flashing.
6.
Remove any HP Jetdirect or other EIO cards, and then try to turn the product on again.
NOTE:
If the control panel display is blank, but the main cooling fan runs briefly after the product
power is turned on, try printing an engine-test page to determine whether the problem is with the
control-panel display, formatter, or other product components. See
Engine-test button
on page
376
.
370
Chapter 3
Solve problems
ENWW