abbas
join:2002-10-23
San Francisco, CA
| [Connection] strange problem
Last week I got my Cable and it had been working great. Today I powercycled for the 1st time only to find out it wasnt connecting, all 4 lights on my RCA DM305 were blinking. I thought maybe MAC address is verified so I connected it directly to PC and still 4 lights blinking for 15 min.
I called tech support and the guy was clueless, scheduled a tech guy on Tuesday sighting 'internal' problems. Out of frustration that it was working before powercycling and now its not, I hooked it up back to the router and WALLAH! it started working again.
Any idea what happened and how does the cable modem connection authenticate itself to Comcast. Also I cant get diagnostics page thru router, workaround would be appreciated |
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I know exactly what
@attbi.com
| Your RCA 305 series modem has a cheap Sino America power supply. The power supply has enough current or power available to run the modem logic board but not the transmitter reciever. Your modem is stuck trying to download the TFTP config file or the TOD information. If you look at the 192.168.100.1/moreinfo.html page, you will see the Signal to Noise ratio moving all over the place. Ask a friend who has an RCA 105 modem if you can borrow the power supply from his modem to verify. Or, a 12 Volt supply from Radio Shack or something that fits. When the problem goes away, you know the power supply that came with your 305 is it. I have seen this problem at least 10 times this year. Not too common but it is happening. |
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oh yah
@attbi.com | reply to abbas
And, the working before power cycling thing.... that is the classic symptom. Except I get my techs to run the factory reset to test for this condition. Good luck. |
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abbas
join:2002-10-23
San Francisco, CA | reply to abbas
Interesting, I'll try it out with a new power supply. It should be 12 volts and 20 Watts? |
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well
@attbi.com
| reply to abbas
It should be around 12 Volts and 1000 milli amps. The new model Sino American supplies that work are 11 volt 800 milliamp. But, I have had the 16 volt, 1.2 amp supplies running on a 305. Worked just fine. I just saw another modem like this today on my trouble call route. Fixed it with a new power supply. |
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abbas
join:2002-10-23
San Francisco, CA | reply to abbas
Mine says 11V and 800 milli amps. Should I get a new adapter or just keep pushing this one?
Internet speed has gone down to 700K a few times but I dont think its the power. |
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Look at
@attbi.com
| reply to abbas
Look at the diag page. 192.168.100.1/diagnostics.htm. Look at the SNR value... if it drifts, you probably have a bad power supply problem. Also, if you do the factory reset on the modem (hold reset until all five lights come on) and the modem fails to syncronize you have a bad modem or supply but usually it is the supply. |
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abbas
join:2002-10-23
San Francisco, CA | reply to abbas
SNR looks stable but powercycle issues. |
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abbas
join:2002-10-23
San Francisco, CA | reply to abbas
today i saw my SNR varying b/w 33.5 and 35.2 dunno if thats all over the place. |
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