Agilent Technologies E4356A manual Selftest Errors, Power-On Error Messages

The line fuse is located inside the power supply. To change it, proceed as follows:

l. Turn off the front panel power switch and unplug the line cord from the power source.

2.Remove the power supply dustcover as follows:

a.Remove the four screws securing the carrying straps and dustcover.

b.Spread the bottom rear of the dustcover and pull it back to disengage it from the front panel.

c.Slide the dustcover back far enough to expose the line fuse (1).

3.Observe the input rail LED under the RFI shield (see Figure E-3 in Appendix E). If the LED is on, there is still hazardous voltage inside the unit. Wait until the LED goes out (this may take several minutes) before proceeding.

4.Connect a dc voltmeter across test points TPl and TP2 (Figure E -3). It may be necessary to remove the RFI shield in order to reach these test points. (The shield is secured by four screws on each side.) When the voltmeter indicates 60 volts or less, it is safe to work inside the power supply.

5.Replace the fuse with one of the same type (see Table 1-4 in Chapter l). Do not use a slow-blowtype fuse.

6.If you removed it in step b, be sure to replace the RFI shield.

7.Replace the dust cover.

8.Connect the line cord to the power source.

9.Turn on the front panel power switch and check the operation.

￿Power Fuse  Line Filter  Rear of Power supply

Figure 3-1. Line Fuse Location

Error Messages

Power supply failure may occur during power-on selftest or during operation. In either case, the display may show an error message that indicates the reason for the failure.

Selftest Errors

When a selftest error occurs, it prevents all front panel operation. The display may show either a power-on error message or a checksum error message.

Power-On Error Messages

Power-on messages appear as: En- - - - - -

Where "n" is a number listed in Table 3-3. If this occurs, turn the power off and then back on to see if the error persists. It is possible to recover from the EE CHKSUM error (see "Checksum Errors"). If any other message persists, the power supply requires service.

Turn-On Checkout 25