Checks at the Central Office

• Do not draw power from a line with dial tone. The loop extender power supply must be fed by no less than 16 AWG wire to work properly.

• Is the LED on the power supply on and solid?

• Is the power supply grounded?

• Check the output of the power supply, do you get 116vDC or 155vDC (Depending on model)? The voltage level may fall by 3-5 volts when attached to a loop extender.

• Sometimes SNR margin and sync rate settings can conspire to prevent synchronization on a line that is perfectly acceptable for service. Setting the minimum upstream and downstream data rate to 32k and target SNR Margin to 4 will allow you to sync if it is at all possible, then you can decide what you want to do from there.

• Check your DSLAM defaults for SNR Margin. SNR Margin 6 is considered normal for data services, but may show tiling on video services. For video services 8 or 10 is normal SNR Margin. The bandwidth estimate is based on SNR Margin=6. If your SNR is higher, you will get slower connect speeds. If your SNR is much higher than 10, you may have difficulties in getting connections on long loops. If it is lower than 6, your customer will complain about CRC errors.
  

Checks at the Pedestal

• Verify that you are getting 116vDC or 155vDC (Depending on model) on the power pair with no load (disconnected from the blue pair of the loop extender). When attached to the extender, power should be diminished by about 1v per thousand feet.

• DO NOT put the power supply in the pedestal.

• Is the LED on the Loop Extender on? Blinking indicates power on all models except the AER800-1P (for AER800-1p Solid LED indicates power). Solid LED indicates the extender hears tones although it may be from adjacent pairs.

• Is the Loop Extender grounded?

• Does the loop resistance match the numbers predicted by the calculator? Check both power pair and service pair. If not, re-check distances, connections and eliminate loads.

• Does modem sync at the pedestal without the loop extender? The sync rate at this location is the maximum the extender can deliver down range. If you can't get sync, the loop extender will not work at this location. You must clean up the line or move the loop extender closer to the C.O.

• Does the modem report attenuation similar to that predicted by the estimator?

• Does the modem run without errors?

• Does the modem report SNR Margin=6 to 10?  (see C.O. checks)
  

• Does the modem sync with loop extender and LA800? LA800 is needed to sync when you are within 200 ohms of the extender. The LA800 will limit your maximum bandwidth, so do not worry about the sync rate.
  

• Does the line run without errors?

Checks at the Customer Premise

• Give the modem a little extra time to sync. The loop extender needs up to twice the normal amount of time so it can experiment with different gain levels.

• Does the modem sync at the rate predicted by estimator “Bandwidth with Extender”.

• If you are on a very long loop and you can get sync but you don't like the data rate, consider adding a second extender.