Troubleshooting; Mid Board Or Coaxial Switch - Keysight Technologies E8257D Option H30 User Manual

E8257D Option H30

Troubleshooting

If there is no signal a problem has occurred. First check the equipment setup, verifying outputs
on the sources and connections. Refer to
Verify that the E8257D Option H30 Upconverter switch is working:

MID Board or Coaxial Switch

The following procedure will aid in determining whether the MID board or the coax switch
(87222E) is functional.
Step 1. Select upconverter mode on/off, then listen for the coax switch to click. If it doesn't
click, check the ribbon cable connection to the switch (under switch/mixer assembly).
Remove the switch end of the cable from the switch and verify: 

pin 1 for +32 Vdc, 
pin 7 for +5 Vdc or 0 Vdc 
pin 8 for +5.2 Vdc 
pin 9 for Ground

If the voltages are incorrect, verify the ribbon cable connection to the MID board
assembly. The ribbon cable should be connected to J14.
Step 2. Cycle the upconverter mode on/off repeatedly while looking at pin 7 voltage. Pin 7
should toggle from +5 Vdc (upconverter mode on) to 0 Vdc (upconverter mode off). If
pin 7 voltage does not toggle, either the MID board or a configuration error is at fault.
Consult with Keysight Service for repair. Refer to
Assistance" on page
Step 3. If the voltages and control signal are present at the ribbon cable as verified in step 1,
reconnect the ribbon cable to the coax switch and select upconverter mode and toggle
it ON/OFF. 
To verify the switch is not ultra quiet, measure the ports on the coax switch while
toggling the upconverter mode. 

(Coupler out) PORT 1 PORT 2 (mixer LO input)
(Atten. input) PORT 4 PORT 3 (mixer RF output)

Port 4 should connect to port 3 in upconverter On mode and port 1 in upconverter Off
mode. If it doesn't, replace the 87222E coax switch.
User's Guide E8251-90072
Figure 4 through
17.
Figure 7 .
"Keysight Support, Services, and
Troubleshooting
7