Keysight Technologies N5224/5A Service Manual page 85

Troubleshooting
Power Up Troubleshooting
If any one individual voltage supply from the A20 power supply develops
an over-voltage or over-current problem, all supplies are affected. The
cause of the over-voltage or over-current condition can be the A20 power
supply itself, or any assembly to which the A20 power supply provides
voltage. To isolate the cause, continue to the assembly removal process as
described in the section titled
page
Table 4-1 Power Supply Measurement Points
Test Point Supply Name
TP517 Analog Ground
TP509 +15 V analog
TP511 +9 V analog
TP515 +3.3 V analog
TP513 +5.2 V analog
TP501 +15 V standby
TP504 +32 V analog
TP512 −15 V analog
If All Supply Voltages are Present
If all of the supplies have measured within tolerances, and the instrument still
is not functioning properly, refer to
page
If Any Supply Voltage Is Missing
Disconnect the line-power cord before removing any assembly.
Procedures described in this document may be performed with
power supplied to the product while protective covers are removed.
Energy available at many points may, if contacted, result in personal
injury or loss of life.
You must sequentially remove all of the assemblies, taking care to disconnect
the line power cord before each removal, and then measure the supply
voltages after each removal.
If the missing supply voltages return to a "power on" condition after removal of
an assembly, suspect that assembly as being defective.
Remove the network analyzer assemblies in the order specified in the following
steps (refer to
Keysight N5224A/25A Service Guide
4-9.
Expected Level
(Vdc)
0 V
+15.0 ±0.1
+9.0 ±0.1
+3.3 ±0.1
+5.2 ±0.1
+15.0 ±0.1
+32.0 ±0.1
−15.0 ±0.1
4-14.
Chapter 7 for removal instructions).
"If Any Supply Voltage Is Missing" on
Test Point Supply Name
TP516 −5.2 V analog
TP514 −7 V analog
TP500 Digital Ground
TP502 +5.1 V standby
TP503 +12 V digital
TP507 +3.35 V digital
TP505 +5.1 V digital
TP519 Digital Ground
"Front Panel Troubleshooting" on
Expected Level
(Vdc)
−5.2 ±0.1
−7.0 ±0.1
0 V
+5.1 ±0.1
+12.0 ±0.1
+3.35 ±0.1
+5.1 ±0.1
0 V
4-9