Agilent Technologies N5242A - Page 83

Service Guide N5242-90001 4-9
PNA Series Microwave Network Analyzers Troubleshooting
N5242A Power Up Troubleshooting
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 “Front Panel Troubleshooting” on page 4-13.
If Any Supply Voltage Is Missing
WARNING 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 Chapter 7 for removal instructions).
1. Unplug the A19 test set motherboard ribbon cable from the A19 test set motherboard
(refer to “Removing and Replacing the A19 Test Set Motherboard” on page 7-26).
1. Unplug the A19 test set motherboard to A20 IF multiplexer board ribbon cable from
the A20 IF multiplexer board (refer to “Removing and Replacing the A20 IF
Multiplexer Board” on page 7-28).
2. Unplug the front panel interface cable from the A1 front panel interface board (refer to
“Removing the A1 Front Panel Interface Board and Keypad Assembly” on page 7-10).
3. Remove the A12 SPAM board (refer to “Removing and Replacing the A4–A13 Boards”
on page 7-14).
4. Remove the A8 source board (refer to “Removing and Replacing the A4–A13 Boards” on
page 7-14).
Table 4-1 Power Supply Measurement Points
Test Point Supply Name
Expected
Level (Vdc)
Tes t Point Supply Name
Expected
Level (Vdc)
TP517 Analog Ground 0 V TP516 -5.2 V analog -5.2 ±0.1
TP509 +15 V analog +15.0 ±0.1 TP514 -7 V analog -7.0 ±0.1
TP511 +9 V analog +9.0 ±0.1 TP500 Digital Ground 0 V
TP515 +3.3 V analog +3.3 ±0.1 TP502 +5.1 V standby +5.1 ±0.1
TP513 +5.2 V analog +5.2 ±0.1 TP503 +12 V digital +12.0 ±0.1
TP501 +15 V standby +15.0 ±0.1 TP507 +3.35 V digital +3.35 ±0.1
TP504 +32 V analog +32.0 ±0.1 TP505 +5.1 V digital +5.1 ±0.1
TP512 -15 V analog -15.0 ±0.1 TP519 Digital Ground 0 V