Keysight N9010A EXA Service Guide 333
CPU/Disk Drive Troubleshooting
A4 CPU Description
Power Supply Control
The power control line from the front panel momentary power switch connects
to the A4 CPU board assembly. When the front panel power switch is turned on
the A4 CPU board assembly pulls the PS_ON line to the A6 Power Supply
assembly to a TTL low level, which tells the power supply to turn on. Once the
+12V D, +5.1V D, and +3.35V D supplies are all on and within specification the
A6 Power Supply assembly pulls the PWROK_H line to a TTL high state, which
then causes the A4 CPU board to come out of reset and boot-up.
Outputs from the A4 CPU board assembly also drive the two front panel power
state LEDs.
Provisions have also been made to allow the CPU board to remember which
power state it was in when a power failure occurs. The instrument will return to
the same power state after a power failure.
To Next Page
Loading...
Need help?
General
