Thread: Modem restarts at every electricity cut

Why the modem restarts during every electricity cut?. My modem is connected to UPS with my computer. During electricity cut my computer works perfectly but my modem restarts. It says redialing and connects again. why is that?

that seems strange.
try inter-changing the points of UPS to which the computer & modem is connected.

i also have the same problem.i am using a HP UPS.

hmmm strange... use some dialup utility to get out of this..

try this , just a small test , connect only your modem to your UPS , and nothing else , then switch off power to the UPS ( so that it runs on battery ) , now check the modem , does the POWER LED blink? does the DSL LED blink?

Easiest solution - Just change the plug on ur modem power plug to match the socket of your UPS.

Most probably the people in this thread plugged in the telephone plug into the UPS and are wondering why the modem dies on a power cut.

you might check your UPS for sticky relays and get them replaced.
The relay contacts get pitted after some use, due to contact sparking.

An adsl modem or wifi router does not need more than
9V or 12V AC or DC at max 1 Amp usually.
Most modems get disconnected during the transient period,
when power outage is there. The change over should be
fast and normal UPS have a transient time of about 24 ms.

To avoid this we may try ONline UPS where double conversion
takes place. AC to DC again DC to AC. ( Costly compared to UPS).

A simple solution is to connect the modem power adapter
DIRECTLY to a 12 Battery with suitable circuits.
If the output is 9V or 12 ~ AC or
9V or 12 V DC = ( check polarity of out plug plug Important )

As the UPS has a 12 V battery this can be tried.
Mention your Modem's make & power adapter details, for further
feedback.

Check your UPS Documentation, some UPS only have 2 points which provide backup and a third one which functions as a spike buster. Try changing the connections and see if the same happens when u switch off the power.

Either or, the UPS may face a cut off because of the Load --- very unlikely

Originally Posted by essbebe

Most modems get disconnected during the transient period,
when power outage is there. The change over should be
fast and normal UPS have a transient time of about 24 ms.

this was the only reply i was looking for and it sounds very logical and satisfactory.
i also had the same problem.modem restarting with every power cut.then i connected my modem directly to the power supply,as i am connected in pppoe mode,i sometimes need to switch off my modem when not using internet.