Interpreting Post Diagnostic Front Panel Leds And Audible Codes - HP mt22 Maintenance And Service Manual

Interpreting POST diagnostic front panel LEDs and audible codes

This section covers the front panel LED codes as well as the audible codes that may occur before or during
POST that do not necessarily have an error code or text message associated with them.
WARNING!
board. To reduce the risk of personal injury from electrical shock or hot surfaces, be sure to disconnect the
power cord from the wall outlet and allow the internal system components to cool before touching.
NOTE: Recommended actions in the following table are listed in the order in which they should be
performed.
Not all diagnostic lights and audible codes are available on all models.
Table 8-3 Diagnostic front panel LEDs and audible codes
Activity
White Power LED On.
White Power LED flashes every 2
seconds.
Red Power LED flashes two
times, once every second,
followed by a 2 second pause.
Beeps stop after fifth iteration,
but LEDs continue until problem
is solved.
Red Power LED flashes four
times, once every second,
followed by a 2 second pause.
Beeps stop after fifth iteration,
but LEDs continue until problem
is solved.
Red Power LED flashes five
times, once every second,
followed by a 2 second pause.
Beeps stop after fifth iteration,
but LEDs continue until problem
is solved.
72 Chapter 8 Diagnostics and troubleshooting
When the computer is plugged into an AC power source, voltage is always applied to the system
Beeps
None
None
2
4
5
Possible Cause Recommended Action
Computer on. None
Computer in Suspend to No action required. Press any key or move the mouse
RAM mode (some models to wake the computer.
only) or normal Suspend
mode.
Processor thermal 1.
protection activated:
A fan may be blocked or not
turning. 2.
OR
The heat sink/fan assembly
is not properly attached to
the processor.
OR
The unit has vents blocked
or is in a location where the
ambient temperature is too
high.
Power failure (power supply 1.
is overloaded).
OR
The incorrect external
power supply adapter is
being used on the unit.
2.
3.
Prevideo memory error. IMPORTANT:
modules or the system board, you must unplug the
computer power cord before attempting to reseat,
install, or remove a memory module.
1.
Ensure that the computer air vents are not
blocked and the processor cooling fan is
plugged in and running, if equipped.
Contact an authorized reseller or service
provider.
Check if a device is causing the problem by
removing all attached devices. Power on the
system. If the system enters the POST, then
turn off the thin client and replace one device
at a time. Repeat this procedure until failure
occurs. Replace the device that is causing the
failure. Continue adding devices one at a time
to ensure that all devices are functioning
properly.
Replace the power supply.
Replace the system board.
To avoid damage to the memory
Reseat memory modules.