Keysight Technologies Option 503 Service Manual page 310

Power Supply/Midplane Troubleshooting
A7 Midplane Board Assembly Troubleshooting
Table 10-1 A7 Midplane Board LEDs and Test Points
Supply/ Description
Signal
POWER_OK Digital Supplies OK
POWER_ON_L Power Supply Enable
POWER_SW_L Power Switch
Pressed
a. With AC mains connected to the instrument
b. POWER_SW_L should only be at a TTL Low state when the front panel power switch is being pressed
310
Referenced Generated
To On
DCOM A6
DCOM A4
ACOM A4
N9030A PXA Signal Analyzer Service Guide
Expected Status
Power On
a
Power Off
LED Test Point LED
(VDC)
Red TTL Low Off
Off TTL High Green
n/a TTL High Green
Test Point
(VDC)
TTL High
TTL Low
b
TTL High