Service manual

52 Troubleshooting
Output Bus Boards A7, A81 and A9 & Chassis Components
Note To remove the A7 Snubber Board, A8 Fast Sense Assembly, A9 Downprogrammer and other chassis
mounted components, first remove the A10 Control Board frame assembly and the two Rectifier Heat
Sinks described earlier. Once the heat sinks are removed you will have access to the A7, A8, and A9
boards as well as other chassis mounted components.
Should you have any difficulty in removing power supply components or boards, contact the Agilent
Technologies Support Line for help.
Shock Hazard: Hazardous voltage can exist inside the power supply even after it has been turned off.
Check the INPUT RAIL LED (A4CR402) under the RFI shield (see Figure 3-14 for LED location).
It 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.
3O Line Choke
Keypad
T900 (top), T901 (bottom)
A2 GPIB Assy
RFI Filter (underneath A4)
A4 AC Input Assy
A5 DC Rail Assy
A3 FET Assy
A1 Front Panel PC Assy
A6 Bias Assy
Display
D900 (top), D901 (bottom)
Fan
A10 Control Assy
Output Bus
A9 DownProgrammer
Slow Sense Assy
A7 Snubber Assy
A8 Fast Sense Assy
Heat sink
24V Bias Xfmr (underneath A5)
L900 (top), L901 (bottom)
Fuses
(underneath A5)
(on top tray)
(above A4)
Figure 3-14. Component Locations (Top Cover and RFI Shield Removed)