What I now know is that the problem is the power and not from ISP. The frequent almost hourly dropouts to the adsl started when I began using a Powerline Adapter.

The dropouts would affect the router modem as though someone yanked the modem phone cable from the wall and plugged it back. I have two adapters, plugged in an outlet near where the modem cable is and another in my bedroom. Removing it reduces the dropouts greatly. I can not do without i through, and the powerlines themselves work fine. I feel there is a preexisting power problem exacerbated by powerline adapters.

I'm planning on using shielded modem phone cables, would that help? Is there something else I could try? A few more information about the house, its not grounded as its euro plug system and there are plenty of surges because it's third world and bad wiring. I've changed receptacles in the outlets I use, and multimeter gives me stable readings afterwards.

  • 1
    I don't think a shielded cable from the modem to the wall is going to help you since any interference is probably happening inside the wall where the phone cables run parallel to power lines. If you can run a fresh new cable from where the phone line comes in to the house to the modem, that might help (use unshielded twisted pair, shielded cable is hard to ground adequately in a residential environment and can make things worse). Or, alternatively, if you can put the ADSL modem closer to where the phone line comes in, that may help too.
    – Johnny
    Dec 16, 2016 at 1:12
  • you right, tried it and nothing helped. Is running phone cables to the apartment from the cabinet my responsibility or the ISP or the phone company??
    – Altoban
    Dec 31, 2016 at 19:46

3 Answers 3


These adapters are using the electrical wire to transmit data over your power wiring. If there is excessive electrical noise surges or droops this can cause packet loss. Installing a whole house surge suppressor could eliminate surges droop is less common in my experiance and many times is caused by bad connections. Power line monitoring may be the only way to find out if it is the power line causing the problem or the quality of the adapters.


I had a similar problem for months. Solved it by soldering a big 4700 microfarad capacitor across the 12 volt DC power line from the AC adapter. It's essentially a super low-pass filter; close to a very poor man's UPS (about $3.00). Jamie

  • Jamiw yes a massive cap can dampen spikes and sustain the dc voltage through a minor dropout on the dc side if it is a dc supply (some are ac but few are most are DC) as a inexpensive solution I have to give you a one up it may work but it has been a long time since this original question, keep the answers coming a fresh look can be helpful. +
    – Ed Beal
    May 23, 2021 at 3:25

I once had a CRT monitor that would reset my cable modem when it changed resolution. I solved the problem by moving them father apart. Shielding would probably also work. You probably have to sheild the modem against electromagnetic interference, such as with a metal box. Make sure there's ventilation. If the modern is also a wifi router, the shielding will probably block the wifi, so increasing distance between it and the powerline adapter is your best bet. You could try shielding the source of the interference with a metal box.

Shielding the cable will probably help only after you stop the modem from reseting, but it's still worth trying I think.

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    Since this is a very small load a UPS uninterruptible power supply used to power the modem & computer would stop the spikes and provide good power even for times when there are major power drop outs.
    – Ed Beal
    Nov 15, 2016 at 14:07
  • Just be sure to get an "online" or "line-interactive" UPS (as opposed to a "standby" UPS) which are more expensive, but regulate the voltage constantly rather than just providing backup power.
    – gregmac
    Nov 15, 2016 at 14:19
  • Would I need a UPS if modem itself isn't restarting, just the dsl connection ?
    – Altoban
    Nov 15, 2016 at 18:01
  • It depends on whether it's restarting because its power supply is being interrupted or if it's getting interference from your power equipment. If there are power surges but not shortfalls, then it's probably interference and you can try to stop it by adding distance and shielding between the modem and the source of interference. If the modem is actually losing power, you need a UPS or something to maintain power. The UPS will not help you against interference and shielding will not help you against losing power.
    – EL_DON
    Nov 15, 2016 at 19:22
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    Somewhere between the wall power and the modem's core electronics is a power supply that converts AC to DC and this probably has some capacitors in it, which can help smooth out short fluctuations in power. So even if you have a VERY SHORT interruption (like a tiny flicker in the lights), the modem won't necessarily lose power if it's caps can keep it going. This is why I thought of interference first, but the others may be right about needing a UPS. It might be easiest to first separate the modem and the power adapter. The power lines themselves could make interference as well.
    – EL_DON
    Nov 15, 2016 at 19:25

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