Disassembly Procedures; Top Cover; Rfi Shield - Agilent Technologies 6571A Service Manual

2150 IF Err THEN
2160 PRINT "An error occurred during the EEPROM read/write, Check for"
2170 PRINT "programming errors. Initialization data may be incorrect."
2180 STOP
2190 END IF
2200 !
2210 PRINT "Operation complete. Program stopped."
2220 STOP
2230 !
2240 Ps_error:
2250 OUTPUT @Ps;"SYST:ERR?"
2260 ENTER @Ps;Err
2270 RETURN
2280 !
2290 END
Figure 3-18. Initialization and Factory Preset Replacement Program Listing (Sheet 6 of 6)

Disassembly Procedures

Shock Hazard: To avoid the possibility of personal injury, remove the power supply from service before
removing the top cover. Turn off the ac power and disconnect the line cord, GPIB cable, load leads, and
remote sense leads before attempting any disassembly.
Cable connections are shown in Figure 6-2 of Chapter 6 and component part numbers are given in Chapter 5. Reassembly
procedures are essentially the reverse of the corresponding disassembly procedures.
Most of the attaching hardware is metric. Use of other types of fasteners will damage threaded inserts.
Older power supplies use TORX screws for securing the carrying straps. When removing or installing
these screws, use TORX screwdriver size T-15 unless T-10 is specified.

Top Cover

1. Remove the four screws that secure both the carrying straps and the cover to the chassis.
2. Spread the bottom rear of the cover and then pull back to disengage it from the front panel.
3. Remove the cover by sliding it back towards the rear of the power supply.
Shock Hazard: Hazardous voltage can remain inside the power supply even after it has been turned off.
Check the INPUT RAIL LED (A4CR402) under the RFI shield (see Figure 3-20). If the LED is on, there is
still hazardous voltage inside the supply. Wait until the LED goes off (approximately 7 minutes after power is removed)
before proceeding.

RFI Shield

The RFI shield covers most components on the A3 through A6 circuit boards, as well as, many of the chassis-mounted
components. Remove the shield as follows:
1. Remove four screws on each side securing shield to chassis.
2. Lift the RF shield out of the chassis.
3. Connect a dc voltmeter across A4TP1 and A4TP2 (see Figure 3-19). When the reading is 42 volts or less, it is safe to
work inside the power supply.
! Error handling subroutine
! Check for errors
Troubleshooting 69