Maintenance and fault finding
Block Up Converter Systems 6700/6900 series User Guide 103
Resolving inconsistent stream selections
To resolve inconsistent stream selections:
1 Use serial commands on a PC running terminal-
emulating software, a Hand-held Controller 6560, or a
Remote Controller 6570 to switch streams remotely (see
page 76, Switching between streams).
1 Switch streams several times to ensure that the switches
are operating correctly in both streams.
1 If the inconsistent stream selections persist, continue
below at Finding faults in an RF waveguide switch.
Finding faults in an RF waveguide switch
The redundancy controller monitors the tell-back contacts in
the RF waveguide switch.
If Stream 1 is on line:
• position 1 tell-back contact should be closed to the
tell-back common contact
• position 2 tell-back contact should be open
The opposite should be true when Stream 2 is on line.
If the redundancy controller detects that either tell-back
contact is set incorrectly, the BUC Switch or LNB Switch
LEDs illuminate red.
RF waveguide switch faults might be caused by:
• an open or short in the control cable for the switch
• a jammed switch or switch that does not rotate through
its full 90° arc
• a burnt-out coil in the switch
• faulty tell-back contacts
Use Figure 26 on page 104 to check for faults in an RF
waveguide switch.