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Chapter 4
Troubleshooting
Power On Sequence Troubleshooting
Check booting process
If the power on sequence has a problem despite it being powered from the power supply
unit properly, check the following events in this order.
1. With the E4981A plugged in and the power turned off, the orange standby LED should
be on. If the orange LED doesn’t light, check the key flex circuit, display interface
board, A31 board, and relevant cables.
2. When the front panel power switch is turned on, the orange LED should go out and the
yellow-green LED should come on. If the yellow-green LED doesn’t light, check the
key flex circuit, display interface board, A31 board, and relevant cables.
3. Three LEDs (+3.3V, +5V, and PWR_GD) on the A31 board should be on. If the LEDs
don’t light, a problem in the A31 board is suspected.
4. The fan should be rotating and audible. If the fan doesn’t run, it is probably defective.
5. The LED on the display interface board should blink. If the LED doesn’t blink, check
the display interface board, the A31 board, and the relevant cable.
6. The firmware revision and hardware option information along with copyright
declaration should be displayed. If nothing is displayed, check the LCD, display
interface board, inverter board, and the relevant cables.
7. The power on test should be executed once automatically before the measurement
starts. If the power on test fails, an error code or an error message is displayed. For
more details, refer to “Troubleshooting using service function”.
8. The measurement view should be displayed.
9. If the following error message
A31 EEPROM write error
is displayed during the
measurement process, a problem in the A31 board is suspected.
10. If the following error message
CPU Bd EEPROM write error
, or
CPU Bd FLASH
ROM write error
is displayed during the measurement process, a problem in the
PPMC PCA is suspected.
11. If the following error message
Fan failed
is displayed during the measurement process,
a problem in the fan is suspected.
12. If the following error message
Power failed
is displayed during the measurement
process, a problem in the power supply is suspected.
Summary of Contents for E4981A
Page 1: ...Keysight E4981A 120 Hz 1 kHz 1 MHz Capacitance Meter Service Guide ...
Page 2: ......
Page 13: ...Contents 11 L 145 M 145 N 145 O 146 P 146 Q 146 R 147 S 147 T 147 U 148 Warning Message 149 ...
Page 14: ...12 Contents ...
Page 70: ...68 Chapter4 Troubleshooting Performance test failure troubleshooting ...
Page 84: ...82 Chapter5 Replaceable Parts Replaceable Parts List Front Panel Figure 5 12 Front Panel ...
Page 132: ...130 Chapter7 Post Repair Procedures Post Repair Procedures ...
Page 138: ...136 AppendixB Firmware Update Update the E4981A firmware using USB cable ...
Page 142: ...140 AppendixC Power Requirement Power Requirements ...