HP j6700, Service Handbook

Page: 72 / 152

72 Chapter 3
Troubleshooting
Using the System Board LEDs for Troubleshooting
There are six LED blink sequences supported by the System Controller. The LED blink
sequences are shown in Table 3-3. Note that each blink of the LED represents a tenth of a
second (0.1 sec.).
If the FANS LED is ever stuck either ON or OFF, a system problem has occurred. This
system problem is most likely an I2C bus hang. A potential fix may be to check that the
power supply cables are correctly plugged in. If this does not work, call you local HP
Support Representative.
VRM0 Green This light, when on, indicates that the
voltage regulator module is working
correctly for processor zero. The
default state for this light is on.
FETCH Green This light, when on, indicates that one
or both processors is fetching code. The
default state for this light is on.
FANS Yellow
(blinking) Note that the yellow light blinks a
heart beat when the system is working
correctly. See Table 3-3. for more
details for interpreting the blinks of
this light.
Over Current Red This light, when on, indicates there is
a short somewhere in the system. The
default state for this light is off.
Table 3-3. Blink Sequences for the FANS LED
Blink
Sequence
Number LED Blink Sequence
(black dot represents 0.1 second LED on; white dot
is 0.1 second LED is off) Description
System Controller Non-error Blink Sequences
1
● ❍ ● ❍ ❍ ❍ ❍ ❍ ❍ ❍
System controllers
normal heart beat.
2
● ● ● ● ● ❍ ❍ ❍ ❍ ❍
This is a transient
state shown by the
system controller at
power up.
3
● ● ● ● ● ● ● ● ● ● ❍ ❍ ❍ ❍ ❍ ❍ ❍ ❍ ❍ ❍
System controller’s
transient state.
There is no system
problem.
Table 3-2. Interpreting the System Board LEDs
LED Name LED’s Color
When On Description