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dsl drops at 8:50 PM EST the past three nights


dsl drops at 8:50 PM EST the past three nights

My DSL works fine up until about 8:50 PM EST.  At which point, I get the dreaded flashing red LED.  The problem persists through the night (i.e. still flashing red) in the morning when I get up, but has fixed itself by the time I get home.  Then rinse, recycle, and repeat.


My connection has worked (by worked, I mean it would be slow and need rebooting often during the week) for the past ~15 months, but I called on Monday to clear up a billing issue and they offered an upgrade to 3.0 MB instead of 1.5 MB at no charge.  Since then it has gone out at 8:50 PM EST every night.


I spend an hour on the phone in the afternoon 3 days ago because of issues and we went through the whole list to get it up and running, but 5 minutes after I was off the phone with the tech, it crashed again.  So, I went to forums to see what I needed to do to change options on the modem to fix the line.  Since, then no crashes during the day, but still crashing at 8:50 PM EST.


So, I'm looking for suggestions as to what could be the issue and solutions on how to fix.  I highly doubt it's the location because it has worked for the past 15 months.  So, interior location is unlikely.  My initial thought after reading the forums, is that with the upgrade in speed, I'm now receiving EMI from the street lights maybe.  Any help would be appreciated.  Thanks.

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Re: dsl drops at 8:50 PM EST the past three nights

Hello sharbin1,


We apologize for whatever inconvenience this intermittent connection issue has caused.  There are many sources of regular loss of DSL sync, most of them being non-persistent sources of EMI/RFI (Electromagnetic Interference/Radio Frequency Interference). Below lists several. If one of the sources below is identified to cause the issue, attempt to isolate the problem.  If the EMI/RFI source cannot be identified inside the home, look for external ones. Look for continuous external events that relate to the time of the loss of connection, then investigate and see if there is RFI involved in any way.


Here are potential causes for periodic loss of Sync.  Cause, Effect and some solutions identified on every source.


1. Master Clock System - Master Clock Systems are installed in schools, factories, and hospitals. These systems send out a carrier current signal on the AC distribution network once every hour, on the 58th or 59th minute, for either 8 or twelve seconds. This signal has the ability to synchronize electronic clocks, sometimes miles from the facility. The customer may lose sync briefly on the hour, every hour.


2. Street Lamp Street lamp can cause loss of sync when AT&T or Power Company facilities are not bonding correctly. The customer may lose sync during the evening and early morning when the street lamp is lit.

Contact our helpdesk and advise them of specific conditions when sync is lost. This may require a network dispatch to test for power influence.


3. AM Radio Tower - Customer lives close to a huge AM Radio Tower.

Customer may also have an issue with hearing radio announcers over the phone, stopped when filters were installed. Customer cannot surf or pull an IP for a few hours every afternoon. ADSL light flashes intermittently. Customer would be able to surf early in the morning, sometimes later.  Contact our helpdesk to put customer on a Noise Profile.


4. Alarm System Alarm Systems can cause the customer to lose sync and/or connection at regular intervals, usually when the alarm system or the alarm company sends info back and forth. The solution for this is to Filter the alarm system. If AT&T-provided filters are not compatible, some alarm companies will provide them. Otherwise, you can obtain them from third-party filter manufacturers.


5. Half Ringer Sync loss (or modem freezing when the phone rings) can also happen with a Half Ringer. The half ringer is also called a Maintenance Unit and many times it is buried on the subscriber side of the NID.


6. Sunlight/Temperature - When the sun shines on a remote, it causes heating and a slightly defective or marginal card can lose sync until the sun moves or the remote gets in the shade. Most CO's have no windows, but if they did, the sun could shine in on a card rack and cause the same symptom until the sun moved.  A marginal or defective splitter at the NID that gets exposed to either extreme sun or extreme cold can cause loss of sync.  Sync is lost regularly with changes in temperature or sun exposure. This may be indicated if sync loss happens every night after it gets dark or other times of day with temperature or sunlight extremes.


7. Moisture - A dirty, moist or loose connection somewhere is the most common cause of periodic loss of sync. Sync loss may occurs more frequently after storm or extended inclement weather.


8. Microwave Oven - Microwave Ovens work in the 2.5 GHz range. An old, "leaky" oven, maybe with a defective door latch, too close to the modem (even on the opposite side of a wall) may cause loss of sync. You may even Lose sync when oven is in use. Move or unplug microwave to test, replace or permanently move if necessary.


9. RF-timer Remote-controlled Lawn Watering System - RFI from Timer on Customer or neighbor's Remote-controlled Lawn Watering System causes loss of sync. Sync lost when watering system is in use or is being shut on or off. Ask customer or neighbor to change the time that he waters his lawn to compare and test.


10. Speed Measurement Radar Gun, Police-Issue or Otherwise Radar-based devices can cause loss of sync due to EM interference on the line. Sync lost when a radar gun is used in close proximity to DSL line --- in one case, a AT&T customer would lose sync every night when a police officer used the cu's driveway as part of a speed trap.


11. Shortwave Radio or "Ham" Radio Transmissions Electromagnetic signals in the short wavelength frequencies (1500kHz and above) are known to cause EM interference with DSL lines. Sync lost when shortwave electromagnetic signals are emitted in close proximity to a DSL line --- in one case, a AT&T customer would lose sync nightly at the same time his neighbor activated a shortwave radio (ham radio) system. Ask any shortwave radio (ham radio) operators in close proximity to the DSL line to transmit at a different time or from a different location.


If intermittency continues after the interference is removed, is is highly recommended to call our 24/7 technical support helpdesk for further assistance. This way, we can run necessary line tests to further diagnose the issue. You may reach them at the following numbers:


1 888 321 2375 if you are from these states - KY, TN, NC, SC, LA, MS, AL, GA, FL; and

1 877 722 3755 if you are located in CA, NV, KS, MO,  OK, AR, TX, WI, MI, IL, IN, OH, CT.

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