HP Vectra VL800 Troubleshooting Manual page 13

NOTE
Pre-Boot Diagnostics
Case 3 — Boot Process Fails and Monitor is Blank
When the power button is pressed, the hard disk drive or fan can be
heard, but the PC does not boot. The monitor remains blank and the
status LED is red (Desktop) or yellow (Minitower). The PC has
detected a hardware error.
Hard disk drive and/or fan can be heard.
•
Monitor remains blank.
•
Status LED is RED
•
Beep code is emitted.
•
Before removing the cover, always switch off the display and PC.
Disconnect the power cord and any accessory cables. When checks
have been completed, close the PC and reconnect the power cord and
accessory cables. Verify that the PC boots correctly.
When your PC starts up, the BIOS performs a series of pre-boot checks
followed by the Power-on Self Test (POST) to test your hardware
configuration for any problems. If a problem is detected during the
POST, an error is displayed on your PC's monitor.
If, however, a pre-boot test fails, it will emit an audio signal.
The Pre-Boot Diagnostics emits an audio sequence with two kinds of
sounds. The first is an unusual series of tones that indicate an anomaly
has been detected. This series of sounds also contains an electronic
signal that can be sent through a telephone line to an authorized
helpdesk or HP Support, if necessary. This signal cannot be interpreted
by the human ear. However, it can be decoded by helpdesk equipment
to extract the PC model and serial number.
The second type of sound is a series of long beeps that indicate a
particular error. If you hear a series of beeps, you should count them as
this will help you detect the cause of the problem.
Case 3 — Boot Process Fails and Monitor is Blank
(Desktop)
or YELLOW
1 Your PC Does Not Start Correctly
(Minitower).
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