Specifications

5 Troubleshooting
90 Series N6700 Service Guide
Preliminary Checkout
Is the instrument inoperative?
 Verify that the AC power cord is connected to the instrument.
 Verify that the front-panel On/Standby switch has been pushed.
Is the display working?
 If the display is hard to read, but front-panel LED is lit and the
fans are working, the display contrast setting may be too light or
too dark. Use the front panel menu to set the display contrast.
Does the instrument fail selftest?
 Remove all external connections to the instrument.
 Check that modules are installed next to each other, starting with
slot 1. If there are any empty slots (or filler modules) between the
power modules, the power system will not operate.
 Check that the mainframe has the latest firmware installed.
 Turn off the unit and cycle power to run selftest again.
If the supply passes selftest and there are no obvious faults, perform
the verification procedures in chapter 2 to determine if any functions
are not calibrated, or are not operating properly.
Self-test Error List
The following table documents the self-test error messages. Refer to
Appendix A for other error messages.
Selftest Errors (these errors set Standard Event Status register bit #3)
202 Selftest Fail Aux Adc 0 expected <n1> to <n2>, measured <n3>, chan <n4>
Auxiliary ADC failed. n1 and n2 are the expected limits. n3 is the measured value. n4
is the channel location of the failed module.
202 Selftest Fail DACs 0 expected <n1> to <n2>, measured <n3>, chan <n4>
Both voltage and current DACs are at zero. n1 and n2 are the expected limits. n3 is
the measured value. n4 is the channel location of the failed module.
202 Selftest Fail DACs 1 expected <n1> to <n2>, measured <n3>, chan <n4>
Voltage DAC is at zero; current DAC is at full scale. n1 and n2 are the expected limits.
n3 is the measured value. n4 is the channel location of the failed module.
202
Selftest Fail DACs 2 expected <n1> to <n2>, measured <n3>, chan <n4>
Voltage DAC is at full scale; current DAC is at zero. n1 and n2 are the expected limits.
n3 is the measured value. n4 is the channel location of the failed module.
202 Selftest Fail DACs 3 expected <n1> to <n2>, measured <n3>, chan <n4>
Both voltage and current DACs are at full scale. n1 and n2 are the expected limits. n3
is the measured value. n4 is the channel location of the failed module.