16
Section 61246026L6-5, Issue 2
61246026L6-5B
Table H. Troubleshooting Guide
Solution
1. Make sure the HTU-R is properly seating in the housing.
2. Verify that the HTU-C is delivering sufficient simplex voltage to the loops, if line
powered. The HTU-C should apply approximately -137 VDC between loops on
point-to-point circuits or with only one HRE. Circuits with two HREs will apply a
voltage of approximately -190 VDC between the loops. A minimum of
approximately 65V should be present between the HDSL loops at the HTU-R.
3. If steps 1 and 2 pass, replace the HTU-R.
1. Verify that the loop conforms with CSA guidelines (not too long, etc.).
2. Verify that the tip and ring of each HDSL loop belong to the same twisted pair.
3. Verify that loop loss at 196 kHz is not greater than 35 dB.
4. Verify that noise on both HDSL loops is within acceptable limits (see subsection 6).
5. If steps 1 through 4 pass and loop sync is still not available, replace the unit with one
known to be in proper working condition.
Condition
All front panel indicators are
off
.
Power is present and adequate, but
loop sync is not available (LP1
and/or LP2 LEDs are
off
).
7. TROUBLESHOOTING PROCEDURES
Use Table H to troubleshoot the ADTRAN HTU-R.
8. MAINTENANCE
The ADTRAN HTU-R requires no routine
maintenance. In case of equipment malfunction, use
the faceplate Bantam jack connector to help locate the
source of the problem.
ADTRAN does not recommend that repairs be
performed in the field. Repair services may be
obtained by returning the defective unit to the
ADTRAN Customer Service RMA Department.
9. PRODUCT SPECIFICATIONS
Table I lists the HTU-R specifications.
10. WARRANTY AND CUSTOMER SERVICE
ADTRAN will replace or repair this product within
ten years from the date of shipment if it does not
meet its published specifications or fails while in
service.
For detailed warranty, repair, and return information
refer to the ADTRAN Telco Network Equipment
Warranty, Repair, and Return Policy and Procedure
(document number 60000087-10A).
Return Material Authorization is required prior to
returning equipment to ADTRAN.
For service, RMA requests, or further information,
contact one of the following numbers:
ADTRAN Customer Service:
ADTRAN Telco Technical Support . (800) 726-8663
Standard support hours ..................... Monday-Friday
7 a.m. - 7 p.m. CST
Emergency support ......... 7 days/week, 24 hours/day
Sales .................................................. (800) 827-0807
Customer and Product
Support (CAPS) ................................ (256) 963-8722
Repair and Return Address:
ADTRAN, Inc.
Customer and Product Support (CAPS)
901 Explorer Boulevard
Huntsville, Alabama 35806-2807
