Check Booting Process - Agilent Technologies E4980A Service Manual

• If the voltmeter reading is within the limits, the power supply is verified.

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 E4980A 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, A1 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, A1 board, and relevant cables.
3. Three LEDs (+3.3V, +5V, and PWR_GD) on the A1 board should be on. If the LEDs
don't light, a problem in the A1 board is suspected.
4. The fan should be rotating and audible. If the fan doesn't run, it is probably defective.
5. Three LEDs for DC Source, DS Bias, and USB should be on temporarily. If these
LEDs don't light, check the USB board, A1 board and the relevant cable.
6. The LED on the display interface board should blink. If the LED doesn't blink, check
the display interface board, the A1 board, and the relevant cable.
7. Three LEDs for DC Source, DC Bias, and USB should go out.
8. 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.
9. 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".
10. The measurement view should be displayed.
11. If the following error message A1 EEPROM write error is displayed during the
measurement process, a problem in the A1 board is suspected.
12. 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.
13. If the following error message Fan failed is displayed during the measurement process,
a problem in the fan is suspected.
14. If the following error message Power failed is displayed during the measurement
process, a problem in the power supply is suspected.
Chapter 4
Troubleshooting
Power On Sequence Troubleshooting
31