Strange problem with my aDSL modem...HELP, lol

[JFRobishow]

Hi everyone,

Well I just got off the phone with my ISP's technical support and they can't help me go figure.

I receive my aDSL connection via a Comtrend CT-301 modem (made for my ISP so no real spec sheet out there)

Yesterday my connection dropped, I thought it was my Wireless router, but I realized my LAN link on the modem was down. I started troubleshooting...

1) Restarted
2) Re-installed NIC's drivers
3) Completely removed the device and re-installed the drivers.
4) Checked RJ-45 cables

All seemed fine so I unplugged the router and went straight from the NIC to the modem...nothing.

I tested the NIC itself by plugging it into my router and it's working fine as I get an IP from the DHCP server and am seen on my LAN.

Now they said they were sending a technician to check, if the modem prove to be faulty it's free, if it's not the modem however they charge me $80.

To make sure I've tried my modem with my laptop, no LAN link. I've switched modem and used my existing cabling and I can get online.

Now no problem there, I figured it was the modem except I've noticed a strange thing just know. After leaving the modem plugged in for over a hour and using the computer (played GTA:SA since I got nothing better to do) the LAN link light suddenly is solid green and I'm able to connect. I decide to test it by unhooking/hooking the RJ-45 no more LAN link...now again after over a hour I'm able to post this from my computer as the LAN link came back up magicaly, lol.

This is so much fun...I don't want to pay $80 but I'm not sure if it's the modem or my setup...what do you guys think any suggestion?

 

[edfair]

Not your setup. If it was the problem would be solid and stay with one system.

Ed Fair
Give the wrong symptoms, get the wrong solutions.

 

[JFRobishow]

Hey ed,

Thanks for the input, I too am thinking it's the modem. Just got back online after rebooting, this time it took a good 2 hours for the LAN link to light up. I'm just wondering what can be causing the modem to act this way...I mean if a RJ-45 port is dead it's dead, no? or if it's not connecting properly you at least have to play with the wire/connector but it just turn on by itself.

I guess I'll get a free new modem soon, it's just strange and being a computer guy I don't like when strange things happen to my computer, lol.

 

[Happo]

There could be 1,000 reasons for it, does it behave inline with the ambient temperature? I saw a modem once that only worked once it reached 46 degrees, believe or not, the staff in this office used to disconnect and put it on top of the coffee machine every morning to heat it up to operating temperature, seriously...this was normal practice!

Get them to look at your modem, I think you have narrowed it down enough.

All the best.

Daniel.

p.s. If you experince a heat wave it may cost you $80.

 

[JFRobishow]

Hey Happo,

It doesn't seems to be related to room temperature. Temperature here is pretty stable as I'm in a basement. Also if the modem reach say the "operating temperature" which would cause it to work, it should still work after unplugging/plugging the cable in less than a second interval.

It's strange, I'm looking everywhere for a RJ-45 loopback device but can't find any in this small town. Oh well...if they say it's not the modem they still have to make it work for $80 so I'll go to bed poorer yet smarter as I'll know what the problem was.

 

[G0AOZ]

How is the modem powered? External 12vdc unit plugged into the mains? Maybe this PSU is not giving a good stable voltage - does it get very hot? Is the modem itself hot to the touch? See if you can exacerbate the problem by, say, heating up the modem - place it on top of your hot water tank, or maybe blow hot air over it from a hairdryer, but be careful not to cook or melt the plastic.

ROGER - G0AOZ.

 

[JFRobishow]

Hi GOAOZ,

The modem is powered by an external source yes, the PSU isn't all that hot not more or less than a normal one giving good voltage. The modem is warm, but nothing unusual there either from personal experience. It seems to be a little better today as I didn't need to wait more than a couple of minutes when playing around unplugging cables and the link was back up...so it could be the heat I guess.

I'll make sure to place it in the fridge before the technician shows up *grin*

 

[tf1]

At this point I would normally suggest resetting the unit to the manufacturers default settings. Then set it up again from the default settings. If it doesn't work then, it would almost definitely be the modem.

Regards: tf1

 

[Sympology]

If you can, check the speed / duplex settings on the Modem.
Each end should match.

If your router / NIC are set to Auto Negotiate, Check that the Modem is. If they are fixed e.g 100/full so should your modem.
If they are set to Auto, try changing to fixed (modem first!)
In theory if theres a mis match they should go down to a common denominator e.g 100/half or 10/half. But sometimes they sulk and just close down.

Worth a try.



Only the truly stupid believe they know everything.
Stu.. 2004

 

[JFRobishow]

Hi Stu,

While I understand what you mean, I don't know how to check those settings on the modem. Don't I need to get into the console for that? If so that's not an option as it's a rented modem which was made just for my ISP so there's not much info. available about it.