Chapter 4 29
Troubleshooting
Power On Sequence Troubleshooting
4. Troubleshooting
Power On Sequence Troubleshooting
Check the Line Voltage and Fuse
Check the main power line cord, power fuse, and actual line voltage to see that they are all
correct. For more information about the line cord and power fuse, see the Power
Requirements in Appendix B.
Check the Power Supply Unit Output
Step 1. Remove the E4980A’s outer cover.
Step 2. Turn the E4980A power on.
Step 3. Measure the output voltage (+3.3, +5, +12, -12 V) of the power supply unit using a
voltmeter with a small probe. The location of each voltage connector on the A1 board and
A3 board is shown in
Figure 4-2.