Service manual

16 Getting Started Chapter 1
Front Panel Features
Figure 1-5 shows the E8408A Front Panel features, and the table describes
the features. When the mainframe is connected to an AC supply and the
Power Switch is pressed ON, the Voltages, Temp, and Fan lights flash
Amber for about one second, and then turn Green. These lights should
remain Green. A flashing Amber light indicates an error condition. In this
case, see
Chapter 3 - Servicing the Mainframe.
Figure 1-5. E8408A Mainframe Front Panel Features
No. Indicator/Switch Description
1 Power Switch Stdby - AC power is applied to the mainframe, but not to installed VXI instruments.
On - AC power applied to the mainframe, and DC power to installed VXI instruments.
2 Voltages Indicator Green - all voltages on the VXI backplane are present. (Does not necessarily indicate
voltages are within VXI specifications.)
Flashing Amber - one or more voltages is not present or is incorrect. The backplane
voltages and allowed variations are listed below:
Voltage
Allowed Variation
+5V +4.875V to +5.125V
+12V +11.64V to +12.6V
-12V -12.6V to -11.64V
+24V +23.28V to +25.2V
-24V -25.2V to -23.28V
-5.2V -5.46V to -5.044V
-2V -2.1V to -1.9V
3 Temp Indicator Green - the power supply temperature is acceptable.
Flashing Amber - the power supply is approaching thermal shutdown.
4 Fan Indicator Green - mainframe cooling fan is operating properly.
Flashing Amber - mainframe cooling fan is not operating.
5 Fan Speed Switch Full - the mainframe cooling fan is operating at full speed.
Var(iable) - the mainframe cooling fan is providing adequate cooling (default setting).
Power
0
Stdby
On
Voltages
1
Temp
Fan Speed
2
Fan
3
Full
Var
123 4 5