Help: Calling all Mac geniuses...

I'm at least as good as AppleCare, but you've just about covered everything. I was going to tell you to look for preferences related to networking or ethernet and trash them, but you've already done that apparently. When you say you trashed a bunch of preferences, were they from the user folder, the Library folder at root level, or both? If it was at the user level, do the systemwide ones.

You've repaired permissions? Run the cron jobs? Repaired prebindings? That's all just voodoo but it can't hurt--but also probably won't help--except for permissions.

Any funny little apps running? Things that have access to the bowels of the OS?

I'd say you're at the point where you should reinstall (archive and install). Just for the record, I never say that. I always try to talk people out of reinstalling because they do it for stupid reasons. This isn't one of those cases. This is a funny little software problem and if you dig deep enough you'll probably find the cause--but it's lots quicker and easier just to reinstall. It's not a big ordeal to do it.

 

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someone correct me if i'm wrong, as i've never done this, but i think archive and install means you do *not* have to reinstall your apps/docs. if that is the case, i would take their advice.

however, just my $.02, my guess is that it is not a software issue. i know you said you still have an ip address and such, but blaming software for this doesn't seem to add up. you mentioned you have a pc--get a crossover cable and try to ping the mac from the pc and vice versa. i'm gonna guess it's a nic card going bad.

 

just archive and install all it dose is replace the system folder and back up all your stuff when you boot again everything will be in place just like it should it only takes 20 mins so just do it

 

Try setting your network card's speed manually to 10mbps, i had a dodgy ntl cable modem that didn't like apple's auto speed thingie.... once set, try rebooting, if not it does sould like the network card could be going bad.

 

If you are using File Vault, turn it off. File vault causes some strange interactions with other parts of the OS and could be the cause of this problem. On my system, File Vault would reset the prefs for my Bluetooth, and it would turn on and be discoverable when I didn't want it to be!

Z.

 

As Hector said, an archive and install won't make you reinstall your apps, it just replaces the system folder (and unix system), so no need to worry, it's a 20 minutes thing.

 

System preferences can remember IPs even though the connection isn't current. Go into terminal and type "ping google.com" and if it send back the packages then go ahead with the archive and install. If it doesn't, i would say you have a bum ethernet port.

 

User Issue?

Have you tried creating a new user and connecting under that log-in? Some times that solves these kind of problems. That being said, I think it's a hardware issue related to the ethernet card. If you can get your hands on one, you could try an USB to ethernet adapter and see if you have the same issue through that connection. That's a pretty expensive option as I doubt you could return it after the test, but it is a way of testing the hardware/software.

Best of luck.

 

similar problem

I had a similar (well the exact same actualy) problem, same symptoms, same lack of good info from applecare, but it turned uot that my problem was due to the fact i had the same instalation of panther (from same 3 cds) on 2 difrent macs (networked through airport) shairing the DSL connection on my eMac with the powerbook. what seemed to be happening is that because the instalations were the same, when the iBook requested packets from the internet, the software base station on the emac became confused and didnt forward the information to the right mac. hope this helps

 

Do a few things for me before I weigh in, if you don't mind.

You can find the necessary applications in HD > Applications > Utilities:

1. Open Network Utility and System Profiler. Using the default pane that's open in Network Utility and the Network pane in System Profiler, check the Hardware Adress and make sure they match. In Network Utility, look to the right and see if the packets sent and received are mostly going through, rather than being dropped.
2. Try a few pings and traceroutes from Network Utility, just to see if your machine is somehow confused by the routing at your ISP. I have no idea how this could affect only one machine, but it's worth checking, even if your ISP and the PC seem to talk to each other. At worst, it shows that your machine is to blame.
3. Check Activity Monitor for any suspicious processes that might be lingering in the system, perhaps as part of a poorly written third party application. Kill them. Also, check the startup items (HD > Library > StartuItems) and log (HD > Library > Logs) folders for odd parts that might have been scattered. I once had a serious issue with drivers for a third party keyboard that didn't function quite right.
4. As a last ditch measure, check the Network panel in system preferences and be sure that the ethernet port is both default and checked in the pulldown menu 'Show,' under the item ' Network Port Configurations.' I'm not even sure the system would let you try to connect without it, but I'm thinking of every possible minor point that might be wrong.