Agilent Technologies E5071C ENA Service Manual page 63

Step 1. Check fan operation and DC monitor LED
If the rear panel fan (blower) doesn't run, a failure in the power supply is assumed. Remove
the E5071C outer cover and check if the following LEDs light:
• +3.3 V and +5 V dc monitor LED on the PCA PCI DSP Card.
NOTE
To check all the outputs of the power supply, measure the dc voltages at the output lead
connectors with a DMM. The dc output voltages and lead color information is provided in
the module cover label of the power supply.
Step 2. Check system fans inside.
If the system fans on the chassis inside the E5071C don't run, problem seems in the analog
base module. In this case, remove the E5071C outer cover and make sure whether the fans
run or not.
NOTE If the power shutdown occurs without a beep, the problem seems in the analog base
module or the CPU Mother Board Assembly. Check BIOS status of CPU Mother Board
Assembly is correct as described in "To configure the CPU Mother Board Assembly and
BIOS" on page 99.
Step 3. Checking with the external monitor
Connect an external XGA monitor to the VIDEO output on the E5071C rear panel.
• If something is displayed on the external monitor, the problem is present around the
LCD. Also check the PCA Front Key and PCA Digital Bridge because the ON/OFF
setting of the LCD backlight is controlled by the PCA Front Key through the PCA
Digital Bridge.
• If nothing is displayed even on the external monitor, the problem seems in the CPU
Mother Board Assembly or PCA Digital Bridge.
NOTE
Check if the PCA Digital Bridge and PCA PCI DSP Board are securely connected to the
CPU Mother Board Assembly.
Step 4. Checking flat cable
Check a flat cable between the PCA Front Key and the PCA Digital Bridge.
Step 5. Check around the backlight
Check Inverter Unit Assembly and a cable between the Inverter Unit Assembly and the
PCA Front Key. Also check the cables between the LCD-TPANEL ASSY and PCA Front
Key. If the cables are normal, check the LCD-TPANEL ASSY.
Chapter 4
Troubleshooting
No Display troubleshooting
63