Keysight Technologies U3047AE04, User'S And Service Manual

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58 User’s and Service Guide U3047-90002
U3047AE04 Service Information
7. Verify the Switch Driver board, “Complimentary Logic LED pairs” shown in
Figure 43
.
a. Ensure that each switch LED pair; one is on and one is off. If not, replace the Switch Driver
board.
b. Verify the RF Switch Drive board voltages by connecting a voltmeter to the four groups of
test points. There are only two switch drive voltage conditions shown. All test points
should have +3 or −3 Vdc present. If the test point voltages are incorrect, remove the
specific RF switch connector from J1- J8.
c. If the test point voltages are incorrect, replace the Switch Drive board.
d. If the test point voltages are correct, suspect a faulty RF switch.
Figure 43 Controller Board
Switch Driver Bd.
J8 J7 J6 J5 J4 J3 J2 J1
= LED INDICATOR (Data Activity Status)
Instrument Rear Panel
Complimentary Logic
Pairs – Port 1 to 3
Switch Path Selected
sw5 sw6 sw7
sw8
sw2 sw3 sw1 sw4
= LED INDICATOR (Switch Logic Status)
off on
sw5 sw6 sw7 sw2 sw3 sw1 sw4 sw8
Test Point Group
(+3 & -3 Vdc)
+ - - +
- + + - = Port 1 to 3
= Port 1 to 2
Controller Status LEDs
Test Set Controller Bd.