Technical data

4-70 Fault Isolation
4.12 Checkout Procedures for the Model 400s System Unit
The following three procedures show you how to check the Model 400s system com-
ponents:
• Procedure 4-8 describes how to check the power supply and related FRUs.
• Procedure 4-9 describes how run the HP-UX ce.utilities.
• Procedure 4-10 describes how to check the calendar battery.
Procedure 4-8. Power Supply Verification for the Model 400s System Unit
Note the following information about power supply operation before you perform this
procedure:
• The power supply delivers dc voltages to all boards, internal mass storage de
-
vices and fans when you press the power-on switch.
• If the power is not completely connected to the motherboard with a normal
load and is turned off, then turned on, it may be a minute or two before the
voltages come up to their normal values.
NOTICE: Before you replace the power supply or a related FRU,
always visually check the power supply harness and other
FRU cables for loose, broken, or pinched wires.
If you find a defective FRU, follow the removal and replace
-
ment procedures in Chapter 5 to replace it.
1. Start this procedure with the system unit power off and the power cord unplugged.
Remove the top cover.
2. If connected, disconnect the system unit from the network. If the system uses
a network connector, unplug it from the network. If the system uses BNC con-
nectors to connect to the network, unplug the BNC ‘T’ from the system unit
connector leaving the network intact through the arms of the ‘T’ connector.
3. Plug in the power cord and power on the system. Measure the + 5, -12 and +12
voltages on the CPU board test points through the holes in the top of the chassis
as shown in Figure 4-21. To measure the -5 and + 9 V dc, you must open the
power supply drawer and measure it at the connector.