Diagnosis During Operation; Troubleshooting Checklist - HP Z240 Maintenance And Service Manual

Verify that the computer is turned on and the blue power light is blue (normal operation) and not red
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(error state).
If you have installed an operating system other than the factory-installed operating system, check to be
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sure that it is supported on your system, go to http://www.hp.com/go/quickspecs.
● Verify that the monitor is turned on and the green monitor light is on. Note that not all monitors are
equipped with LED lights to indicate their functionality.
● Turn up the brightness and contrast controls of the monitor if the monitor is dim.

Diagnosis during operation

● Look for blinking LEDs on the side of the computer. The blinking lights are error codes that will help you
diagnose the problem. Refer to the
audible codes on page 80
and audible codes.
● Check all cables for loose or incorrect connections.
Wake the computer by pressing any key on the keyboard or the power button. If the system remains in
●
suspend mode, shut down the system by pressing and holding the power button for at least four
seconds, then press the power button again to restart the system. If the system does not shut down,
unplug the power cord, wait a few seconds, then plug it in again. If it does not restart, press the power
button to start the computer.
● Reconfigure the computer after installing a non–plug and play expansion board or other option.
● Be sure that all required device drivers have been installed. For example, if you have connected a printer,
you must install a printer driver.
● If you are working on a network, plug another computer with a different cable into the network
connection. There might be a problem with the network plug or cable.
● If you recently added new hardware, remove the hardware and verify if the computer functions properly.
● If you recently installed new software, uninstall the software and verify if the computer functions
properly.
● If the screen is blank, plug the monitor into a different video port on the computer if one is available.
Alternatively, replace the monitor with a monitor that you know is working properly.
● Upgrade the BIOS. A new release of the BIOS might have been released that supports new features or
fixes your problem.
● Press the

Troubleshooting checklist

Before running diagnostic utilities, make sure that the following conditions are met:
The computer is connected to a working electrical outlet and powered on, and the power light is
●
illuminated.
The monitor (for tower or desktop configurations) is connected to a working electrical outlet and
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powered on, and the power light is illuminated.
The monitor brightness and contrast are properly adjusted.
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● The keyboard is operating correctly (press and hold any key and listen for a beep).
● All cables are properly connected.
62 Chapter 4 Diagnostics and troubleshooting
section of this document for information on interpreting diagnostic lights
caps lock key. If the caps lock
Interpreting system validation diagnostic front panel LEDs and
LED toggles on or off, the keyboard is operating correctly.