Keysight Technologies U3047AE04, User'S And Service Manual

Page: 63 / 81

User’s and Service Guide U3047-90002 57
U3047AE04 Service Information
Figure 42 DC Power Status LEDs
RF Switching Failures
Typical failures may be the loss of front panel R, S LED or RF switch control failure. The internal
RF switches used in this instrument are controlled by the +3 and −3 Vdc voltages from the
Switch Driver Bd.
1. Confirm that the PNA and Test Set are properly connected using the Test Set I/O cable
(8120-6818). See Figure 11 on page 16 .
2. Using multiport mode (Option 551), verify that the PNA firmware is correct, and that the Test
Set file is loaded into the PNA. Refer to
“Network Analyzer Requirements” on page 3 .
3. Using the I/O command values, confirm that the correct address and data values are used.
Refer to
“Address and Data Values” on page 35 .
4. Follow the “Non-RF Failures” on page 56 procedure if not already done so.
5. Front Panel R and S indicator LED Check.
a. Confirm that the Test Set Controller Board Status LEDs are On. Refer to Figure 43 on
page 58 . If the LEDs are off remove the Switch Driver board, if the LEDs remain off, replace
the Controller board.
b. If the Status LED’s are On and the front panel Active LED is On, suspect the front panel
LED board or the ribbon cable and replace as needed.
6. Confirm the DC +3 and 3 Vdc voltage LEDs as shown in Figure 42 on page 57 .
Switch Driver Bd.
+5 V
+24 V
+3 V
-15 V
-12 V
+15 V
+12 V
-10 V
+9 V
-15 V
-15 V
-10 V
+5 V
-5 V
+3 V
Test Set Controller Bd.
J8 J7 J6 J5 J4 J3 J2 J1
-3 V
sw1
= LED INDICATOR
(DC Power)
Instrument Rear Panel
U21 Regul DC Output
(For All Switches)
DC
Inputs
U22 Regul
DC Output
U23 Regul
DC Output
U24 Regul
DC Output
U25 Regul
DC Output
U26 Regul
DC Output
U27 Regul
DC Output
U28 Regul
DC Output
U29 Regul
DC Output
U29 U27
U25 U23
U28
U26 U24
U22 U21
DC
Inputs
-3 V
sw2
-3 V
sw3
-3 V
sw4
-3 V
sw5
-3 V
sw6
-3 V
sw7
-3 V
sw8