Service manual

44 Servicing Your Mainframe Chapter 3
Isolating Problems
Replacing Assemblies
This section contains instructions for replacing the basic monitor, power
supply, power supply fan, and impeller.These assemblies are available from
Hewlett-Packard under the part numbers shown in Table 3-2. Contact the HP
TMO Business Center at 1-800-829-4444 to obtain replacement assemblies.
Table 3-1. Isolating Problems Within the HP E840xA Mainframe.
Symptom Action
Flashing Voltages Indicator One or more backplane voltages may be out of specification. Check
diagnostic connector pins 1, 2, 3, 4, 14,15,16. Check for a loose cable
between the basic monitor assembly and the backplane. Replace power
supply if any voltage remains out of specification.
Flashing Temperature Indicator Power supply temperature is high. Mainframe is nearing automatic shutdown.
Check for proper air flow and clearance around the power supply fan(s).
Flashing Fans Indicator Power supply fan or mainframe impeller has failed. Visually inspect to
determine which fan is not rotating. Turn off mainframe to avoid possible
overheating. Power supply fans are not individually replaceable; replace the
power supply.
Monitor indicators are off and
fans do not operate when On
button is pressed.
Check for a loose cable between the basic monitor assembly and the
backplane. Replace the basic monitor board.
No monitor indicators when
mainframe is turned on.
Check diagnostic connector pins 1, 2, 3, 4, 13, 14, 15, 16 to determine if
backplane voltages are within specification and power supply and backplane
impeller are functioning. Replace the basic monitor PC board.
The SYSFAIL indicator will come on and remain on when a VXI module installed in the mainframe fails.
Table 3-2. HP E8400A Replacement Assemblies
Assembly HP E8401A
Part Number
HP E8403A
Part Number
Basic Monitor E8400-66502 E8400-66502
Power Supply E8401-69204
500 W Power Supply
Exchange Assembly
E8403-69204
1000W Power Supply
Exchange Assembly
Impeller (backplane fan) E8400-68501 E8400-68501