Agilent Technologies Agilent 33500 Series Operating And Service Manual page 414

Troubleshooting
Reseat the Boards
Power off the unit, remove the cover. Reseat the processor board and the main board. Power up the unit and see if the
errors 605-609 are still reported at power-on.
Check Power Supplies
Probe the system power supplies and verify they are operating within limits. If any of the power supplies are out of
limit, diagnose the power supply. Otherwise, continue on to check SPI communications.
Check SPI Communications
If you still see errors after reseating the boards, the next step is to probe the SPI communications lines between the
processor board and the main board. First, locate LED DS1001 on the main board as shown below. Cycle power on the
unit, wait until it fully boots, and see whether the main board LED illuminates. The main board LED indicates whether
the FPGA was successfully programmed. The following sections indicate which signal lines to probe on the main board
connector (J201).
Main Board LED Lights up after Boot
This indicates that the FPGA is programmed and running. Most likely there is a communications failure from the main
board to the processor board. Probe the J201, pin 27 line with an oscilloscope, and cycle power on the unit (wait for full
boot) to see if there is activity on the line. Activity should be +3.3 V pulses (isolated). Note that activity ceases once the
instrument is booted.
Agilent 33500 Series Operating and Service Guide 413