Appendix A: Troubleshooting - Black Box V.35 256/ST Series Manual

Appendix A: Troubleshooting

Symptom
LEDs do not light
when the AC
power transformer
is plugged into the 2. Outlet is defective.
wall.
Carrier Detect (CD) 1. If CD is low, possible
LED is low
or
Carrier Detect (CD) wrong position.
LED is high, but
the Drivers aren't
communicating.
Problem
1. Loose power connection.
3. AC power cord is defective.
4. AC transformer is not
plugged into the Driver.
synchronization loss.
2. Test Mode switch is in the
3. DIP switches are set
improperly.
4. Fiber link is connected
improperly.
5. V.35 connections are faulty
or cables are pinned wrong.
APPENDIX A: Troubleshooting
Solution
1. Make sure the AC
connection is flush.
2. Try a different outlet.
3. Remove the cord from the
outlet and check for continuity.
4. Plug it in.
1. Check for ongoing power
loss or break in fiber if CD does
not go high within 60 seconds.
2. Be sure the Test Mode
switch is set to NORMAL on
both Drivers.
3. Check all DIP-switch
settings, especially Reset and
Data Rate, against those listed
in Chapter 3. Make sure both
Drivers are set the same way.
4. Check the ST or SMA connec-
tion on the back of both Drivers.
5. Check V.35 cable continuity
and pinning.
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