HELP! iMac, cable modem won't go.

[stripes]

Desperate for help on this one.

Brand new iMac won't connect to internet through ntl cable modem 250.

Been using same modem same cable etc etc on my old G3 mac for the last 2 or 3 years, no problem.

Apple says must be modem.

NTL say must be iMac.

Me: piggy in the middle.

A) has anyone round here had similar problems?

B) If I want to try and solve it by going out and buying a new cable modem, what sort should I look for, and where can I buy one?


Thanks for your help.


Allen (thankfully G3 set-up is still working!)

[Illuminist]

...Its the iMac.

[Richy99]

you cant buy a new cable modem, it has to come from ntl

i assume you turned the modem off before you plugged it into the imac?

[ShadowTD]

Are you saying the *same* cable modem using the *same* ethernet lead is still working when you plug it into the G3? If so, I'd be inclined to suspect the iMac....

*However* istr something about registering the MAC address of your computer/router and this being tied to your DHCP lease? Or am I talking out of my backside? If this is the case then power off the modem and leave it for a few hours for the DHCP lease to expire and then plug it into your new iMac. What are your settings for Built In Ethernet in Networking in System Prefs? (Yes, I'm a Mac user)

[stripes]

Thanks Shadow, I'll try the big switch off overnight.

It is a brand new iMac. In fact the second brand new iMac. Last week I managed to convince Apple that the first one was faulty, so they sent out another, and, same problem.

ntl say it ain't them, as the G3 is going okay.

but yes, there is something somewhere about the ntl modem only recognising a single MAC address, so the second iMac might be confusing the thing.

I'll turn it all off, and take the plugs out, and try again tomorrow, and post a reply then.


Allen.

[Richy99]

did you actually turn the modem off tho before you connected it to the imac?

all you need to do is turn it off and leave it off for a few minutes then plug it in

[Stuart]

Originally Posted by Illuminist

...Its the iMac.

Doubtful.

[bonzoe]

The NTL network will allow 2 MAC addresses, how do you think techies can connect a laptop to check things when needed?

I've changed PCs, routers and network cards & never had a problem with MAC addresses, and never cloned a MAC address.

Are the iMAC settings the same as your G3? You are using ethernet connection, aren't you? Not USB.

[NTLVictim]

Is it possible to see the modem, and if so, force a new IP request?

can't remember the ip..192.168.100.100? help!

[melevittfl]

Originally Posted by stripes

ntl say it ain't them, as the G3 is going okay.

Don't you mean *was* going OK? Or do you have both the G3 and the iMac connected somehow? If so, how?

Can you describe what cables are connected to what?

Are you using ethernet?

[stripes]

No, the G3 IS going okay.

I have the machines side by side. If I connect the ethernet cable to the G3, power down the modem, repower, switch all on again, G3 works fine.

If I do the same thing to the iMac, no go. I get a constant '169...' address, rather than the proper ntl IP connection.

Last night, I left the modem completely switched off for 20 hours - co-axial out, ethernet out, power out. Turned it on today and same as before, i.e. won't connect to internet.

Could it be that the ntl central system is somehow LOCKED on to my old G3, in some way that the twenty hour switch-off wouldn't cure? NTL claim this is impossible, and won't even talk about the possibility.

What I didn't tell you originally was that last week the iMac was brand new, and had these problems. I convinced Apple that the machine was faulty (having been convinced by the service personnel at ntl), so Apple sent me a SECOND brand new iMac. Same problem. NTL still say it can't be at their end, and Apple, quite understandably, think they've done all they can, barring the almost total impossibility of them supplying two brand new machines each with the same ethernet problem.

Me? I am in despair, as no-one will take responsibility, and I have now spent hours and hours, quite literally, to the Apple Support centre, and to the ntl support line, and have got, precisely, nowhere.

Anyone who can offer a solution will have my undying gratitude!


Allen.

Have you cross-referenced all your system preference settings between the two Macs to ensure the new one is set up correctly?

Did you by any chance use Migration Assistant to copy data and apps from the old iMac to the new one?

It's hard to say what the problem is without having the full facts. It could be something as simple as not having DHCP set in the new iMac for receiving the IP address.

[stripes]

Hello Chris T.

Not completely sure what you mean by cross-referencing. We (Apple and me) have tried connecting using 'ordinary' DHCP, and occasionally manual DHCP (where we did enter various IP, router, etc., addresses), all with no success.

The G3 is OS8.6, the iMac is OS10.4 (Intel), so the way they are set up is only similar, not the same.

No, I didn't use Migration Asst. on setting up the iMac. All I did was turn it on. There is a point in the turning on process where the Mac tries to connect to the internet to register; that was the point (with each iMac) where the message 'unable to connect to the internet' came up.

The iMac, typically of Macs, hasn't got much in the way of setting up. Basically all you do is go to System Preferences, make sure Built-in Ethernet is chosen, even deselect the other options like Airport to make sure they don't interfere, make sure 'DHCP' is chosen rather than the other options (manual DHCP, for example) and that SHOULD be that.

Just a notion (something one of the Apple guys mentioned). Would it be worth me getting a router to plug into the modem, the purpose of which would be (hopefully) that the incoming signal would only care about the modem and router, not what was connected to it. Or is that just another forty quid down the drain? If there is the FAINTEST chance that this would work, I shall be round to my local Maplin before you can say Internet...


Thanks for your interest.


Allen.

[handyman]

Originally Posted by stripes

work, I shall be round to my local Maplin before you can say Internet...

Be careful with maplin, some of their stuff can be very expensive and not as current as other places. To be fair you'll get a good deal on linkys or belkin routers from pc world or dixons (currys digital). They have wireless routers on offer at £40 from time to time.

Originally Posted by stripes

Hello Chris T.

Not completely sure what you mean by cross-referencing. We (Apple and me) have tried connecting using 'ordinary' DHCP, and occasionally manual DHCP (where we did enter various IP, router, etc., addresses), all with no success.

The G3 is OS8.6, the iMac is OS10.4 (Intel), so the way they are set up is only similar, not the same.

No, I didn't use Migration Asst. on setting up the iMac. All I did was turn it on. There is a point in the turning on process where the Mac tries to connect to the internet to register; that was the point (with each iMac) where the message 'unable to connect to the internet' came up.

The iMac, typically of Macs, hasn't got much in the way of setting up. Basically all you do is go to System Preferences, make sure Built-in Ethernet is chosen, even deselect the other options like Airport to make sure they don't interfere, make sure 'DHCP' is chosen rather than the other options (manual DHCP, for example) and that SHOULD be that.

Just a notion (something one of the Apple guys mentioned). Would it be worth me getting a router to plug into the modem, the purpose of which would be (hopefully) that the incoming signal would only care about the modem and router, not what was connected to it. Or is that just another forty quid down the drain? If there is the FAINTEST chance that this would work, I shall be round to my local Maplin before you can say Internet...


Thanks for your interest.


Allen.

Aah, sorry, I hadn't appreciated that you had been persisting with quite such an elderly iMac for so long. Congratulations for keeping on going with OS 8! I'm not certain that the Migration Assistant would work for you anyway, if you don't have a version of OS X on your old machine. Never mind, it was just a thought and shouldn't prevent you from getting the right settings into your new machine anyway.

The iMac should indeed do as you describe. I have set two of them up on my home wireless network and never even needed them to be plugged into my router at any stage. Both immediately detected my wireless network and, as the network is unsecured (very rural and isolated so minimum risk) they just got online straight away.

I think it highly unlikely that two different iMacs would be supplied to you with faulty ethernet hardware so I don't think the fault is in the computer. If you have System Prefs set to use Ethernet, with automatic DHCP, that is all you should need. Either your modem is on the way out - unlikely, as it still consistently works with your old iMac - or, and this is the only alternative I can think of, the network is not wanting to register your new MAC address. In this instance, power-cycling the modem should fix the problem. I notice you have tried that already but you do need to give it more than a few seconds so trying it overnight will be worthwhile.