old router does not start with new power supply

roodap

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Jan 29, 2012
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my Beetel 220BXI ADSL2+ Modem works ok.but the power supply 5V 1A has become intermittent working and disconnects often and all lghts go off and restarts.
i bought a new 5V 1A power supply but it does not help. the router all lamps come up and does not do any thing more.
what differencs in the powersupply causes this. ?
the voltage measures 4V open circuit same as the old one.
the old power supply still works most times and router works as long as the old powersupply works.
can somebody help me in this poersupply replacement trouble ?
 

roodap

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Jan 29, 2012
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18,530
Yes i have made sure power supply is intermittent. even power on lamp does not light up. if tap he power supply it tries to start up.
with new power supply lamps all coming up promptly.
but no start up of router.

again old power supply connected it boots up sometimes.
 
I'm not an electronics expert, but could the polarity be wrong? On some adapters, the center is negative while the outer part is positive. It's reversed on other adapters. Of course, I wouldn't expect any lights if the polarity was wrong.. or possibly it could hurt the unit.