IBM totalstorage 200, Service Manual

Page: 23 / 180

that are illuminated remain that way when the appliance shuts down, provided the
ac power source is good and the power supplies can 5V dc to the
appliance. This feature helps you isolate the problem if an error causes the
appliance to shut down. See “Light-path diagnostics table”.
AC and DC Power LEDs
The AC and DC Power LEDs on the power supply provide status information about
the power supply. See “Power Supply LED errors” on page 27.
Diagnostics panel
Figure 6 shows the LEDs on the diagnostics panel on the system board. See
“Information panel System Error LED” on page 18 for information on identifying
problems using these LEDs.
Light-path diagnostics table
The System Error LED on the operator information panel is on when certain system
errors occur. If the System Error LED on your appliance is on, use the table in
“Information panel System Error LED” on page 18 to help determine the cause of
the error, and the action you should take.
Diagnostic programs and error messages
Note: You will need to connect a keyboard and monitor to your appliance in order
to see error messages.
The appliance diagnostic programs are stored in upgradable read-only memory
(ROM) on the system board. These programs are the primary method of testing the
major components of your appliance.
DASD2
DASD1
VRM
PCI A
PCI B
CPU
MEM
FAN
TEMP
NMI
OVER
NON
PS3
PS2
PS1
Figure 6. Diagnostics panel
Chapter 1. Troubleshooting
7