ADTRAN HDSL2 - Manual (Page 64)

Troubleshooting HDSL2 for General Distribution Installation and Maintenance Practice
54 61223HDSL2L2-5B
Table 14 provides an H2TU-R troubleshooting guide to assist in problem resolution.
Table 14. H2TU-R Troubleshooting Guidelines
Condition Solution
All front panel indicators are
off. 1. Make sure the H2TU-R is properly seated in the housing.
2. Check powering voltage:
• For Span Powered unit (1223026L2) verify that the H2TU-C is
delivering sufficient simplex voltage to the loop.
• For Local Powered unit (1223024L2) verify that –48 VDC is
properly connected.
3. If steps 1 and 2 pass, replace the H2TU-R.
Power is present and ade-
quate, but loop sync is not
available (
DSL
LED is off).
1. Verify that the loop conforms with CSA guidelines (not too long,
etc.). For more information, refer to “HDSL2 Deployment Guide-
lines” .
2. Verify that loop loss at 196 kHz is not greater than 35 dB.
3. Verify that noise on the HDSL2 loop is within acceptable limits.
4. If steps
1 through 3 pass and loop sync is still not available,
replace unit.